Monday, March 24, 2008
During an earth the Richter scale measures how powerful the earthquake is. It measures the energy released during an earthquake. Charles Richter invented it in 1935. The mercali scale measures the intensity of an earthquake. That means it measures how much damage is caused during and after an earthquake to a city. Guiseppe Mercali invented it in 1902. One difference between the two scales is how big each scale is. The Richter scale has ten levels of measuring the energy released from an earthquake, and the mercali scale has twelve levels of measurement that describes the intensity of an earthquake. That’s a main difference between the two scales.
Another main difference between the two scales is the way they measure energy or intensity. The Richter scale is used during an earthquake. Richter scales are used with seismograms to calculate the energy levels of and earthquake. A mercali scale is calculated by a person to decide how much damage was put upon a civilization. The higher the intensity of an earthquake the more damaged a city is. The higher the reading on a Richter the more powerful an earthquake will be.
Another difference between the two scales is the way they calculate energy or intensity. On a Richter scale each level is one hundred times more powful than the last level. So a level two earthquake is one hundred times more powerful than a level one. The intensity of and earthquake is calculated by the damage on a surface to a city. There might be mudslides or fires so the intensity would be at high levels. That’s the difference between the two scales.
Those are some differences between the Richter scale and the modified Mercali scale. They are both very useful to scientists to understand how powerful earthquakes can be. And hopefully scientists will one day be able to predict earthquakes for the safety of people.
Sunday, March 23, 2008
Tokyo, Japan is a society living on an active plate boundary. There are many precautions these people take to handle the effects of volcanoes and earthquakes, many of which will be explained in the following essay.
To reduce damage the buildings have earthquake resistant structures. One part of the structure is base isolation. The building is resting on rollers, so when the ground shakes the rollers move, not the building. Another way of minimizing seismic damage is using Seismic Dampers that act like a car’s shock absorber. The movement may be very large but the dampers absorb part of the energy. A structure may also include ductile materials, like steel, which can tolerate a good amount of inelastic deformation. Of course many things are done that do not have to deal with the building structure, but what the people in the society do for their selves. All the houses are set to standards set by the government, so they are all recognized as safe. Furniture is secured to the walls or ceiling so that nothing collapses during activity, also heavy or large items are to be taken out of top cupboards and shelves moved to bottom ones, where they are less likely to be harmful during tectonic activity. Knowing how and when to shut off the gas of a home is another very important thing the people have learned to handle the dangers. Everyone should know all the exits and keep them clear. One of the most important things these people do is keep a bag for emergencies filled with, food, water, money, flashlights, batteries, radio, and more.
The people of Tokyo, Japan have learned to handle the effects of living on an active plate boundary with ease. Volcanoes and earthquakes are part of their lives and they know how to deal with it. They have many precautions making it easier to deal with. (ME4)
Saturday, March 22, 2008
The Earth was composed of several giant plates, called the Tectonic Plates. On the plates are the continents and the oceans of Earth. The continents were said to have been one big, single, continent called Pangea. Since then, the single continent drifted apart from eachother. About 200 million years ago a sea stretched along the latitudinal area, which today is occupied by the Himalayans. The sea was called The Tethys. The Northern Eurasian land mass and the Southern Indian land mass started depositing large amounts of sediments. The sediments started pouring into the shallow part of the Tethys. The two land masses began colliding with eachother. This phase kept happening over and over. The last major phase happened about 600,000 years ago. These series of phases is what led to the formation of the Himalayas.
Overall, the forces of the Himalayan mountain range was the collision. Also, the deposits from the land masses that filled the sea.
The collison of India and Asia, happened along the convergent boundary.
Today there is still movement in the tectonic plates, due to earthquakes. The Himalayas still rise about 5mm per year. The Himalayas are young, folded mountains.
In conclusion, the theory of the Himalayas in 1912 is the accepted theory, called the Continenal Drift. 200 million years ago is when the two large land masses collided and started forming. Today this is still the accepted theory about the Himalayan mountain range. The Himalayan mountains took a very long time to form. But the forces and time it took to form the mountains, gave us huge and beautiful mountains today.
5:12AM April 18, 1906, San Francisco was struck by one of the highest ranking earthquakes of all time. The massive earthquake ruptured the north most 299 miles of the San Andreas Fault, and destroying over 490 city blocks. Killing about 3,000 people and injuring about 225,000 more. The property damage was a bout 400,000,000 in 1906 money. Most of the destruction occurred from the fires that were ignited from the earthquake. The epicenter was about 2 miles offshore from Mussel Rock, California. The shaking started and lasted about 40-45 seconds long. The earthquake was felt from southern Oregon to south of Los Angeles and as inland as centeral Nevada.
People can educate themselves about earthquakes so they can be familiar with them if they were to happen. Such as learning about aftershocks, this is an earthquake of similar or lesser intensity that follows the main earthquake. It is smart to have a family plan if an earthquake were to happen. Some things in that plan may be knowing the safe spot in each room, physically practice safety drills, have a first-aid handy, know CPR, and having a place where you and your family can reunite if separated. You should prepare your house, and what’s in it. A lot of the damage caused by an earthquake is from objects in your house. During the shaking, cabinets and the things that are in it topple, the windows shatter, and hanging plants and light fixtures fall. You can reduce the risk of injuries and damage to your house by removing, moving, fastening or simply latching the items that are more likely to fall over and seriously injure someone to something that can withstand all of the shaking of an earthquake.
Some safety measures you can take when an earthquake actually occurs are minimizing your movements; only take a couple small steps to a close by place that may be safer. Try not to panic, instead steady yourself and try to think clearly. When you feel an earthquake happening (shaking of the ground), you should duck under a sturdy table or desk. Don’t move or let go of that object until the shaking stops. Stay as far away from bookcases, windows, heavy mirrors, file cabinets, hanging plants, hanging light fixtures, or any other heavy objects that could harm you.
Those are the most important things you should do to prepare your house and yourself if an earthquake were to occur. Even though earthquakes can be extremely dangerous, the precautions and safety measures you can take may someday save your life.
Wednesday, March 19, 2008
Friday, March 14, 2008
After researching the great San Francisco earthquake of 1906, I have come to know what life was like before and after the earthquake.
Before the earthquake, San Francisco was one of the largest and most important ports along the Pacific coast. It was the 9th largest city in the U.S. and it was home to millions of people. Skyscrapers and building were the work place for many who lived in that area. No one was expecting or was prepared to what the 60-year-old city was about to do.
On April 18, 1906 at about 5:30 in the morning disaster struck. An earthquake that could be felt from southern Oregon to South Los Angeles stretching to inland Nevada occurred. It lasted any where from 45 seconds to a minute, which comparing to other earthquakes is a very long time. Building immediately fell down and most caught on fire just seconds after the earthquake. The fire burned for 4 days and 3 nights. The fire department alarm system was destroyed and all forms of communication were lost and the city of San Francisco suffered. One of the hospitals was part way crumbled and about100 patients lost their lives. Not including the 300,000people that had died in trapped buildings or in the fires, so about 200 died elsewhere due to the cause of the earthquake. The after result of the earthquake resulted on more than 500,000,000 1906 dollars. Not to include that the San Francisco banks held more that a 1/3 of the nations gold supplies. The streets were covered with debris and any brick building was crumbled to the ground. More than 300 earthquake cracks were formed.
In conclusion, I learned that before the earthquake of 1906 occurred the people were NOT prepared at all for a natural disaster. Now a little over a century after the tragic event occurred we are well prepared for what will hit us next. But we will never forget the living memory of the great San Francisco earthquake that happened so long ago.
Now they raise from the ashes.
This earthquake was so huge that it is the most significant earthquake. It ruptured the northern most 296 miles of the San Andreas Fault from northwest of San Juan Bautista to the triple junction at the cap Mendocino. Before this terrible earthquake, San Francisco was a beautiful landscape that was home to many people. It had many different varieties of culture. San Francisco had a very unique landscape with old antique buildings, and lush vegetation. Suddenly that changed.
At 5:12 am local time there was a foreshock. Sufficient force wildly threw the San Francisco bay area. Then came the great earthquake 20-25 seconds later near San Francisco. Then a violent shock came with a strong shake 40-60 seconds after the foreshock. Because of the earthquake there were many fires that burned the old beautiful buildings to the ground. Because of the deadly shake and the deadly fires 750 were injured and only 50 people survived and that mean that 700 people died. There were 400,000 people living there before it happens but then after the earthquake over 250,000 were left homeless by the disaster. The city went to a beautiful, unique place to a sad, buried out place.
On the Richter scale it made 7.1. Homes and property were damage during this disaster. Because of the earthquake estimated at $6 billion dollars that will go to fixing San Francisco.
The journey to the center of the earth
First at about 0 miles to about 25 miles deep its jus the rock or crust it is solid. Then u hit the mantle, which is melted rock, and solid rock, which is changed chemically because of the magma. And that is 1800 miles thick then u hit the outer core which is nothing but magma or melted rock the chemicals change again because its all melted no rock its all magma and that is 1400 miles thick then at about a grand total of 32,25 miles deep u hit the pure iron form of the core which is a metal that is 800 miles thick of iron which changes again because from rock to paschal melted rock to melted rock to iron there are many chemical changes because in the mantle the rock is very dense. It can range from 1600 degrees Fahrenheit in the crust at the bottom were the rock begins where the mantle starts that can be up to 4000 degrees Fahrenheit and that is were the outer liquid part of the core starts and that is made of iron and nickel and is ranged 4000 degrees to 9000 degrees Fahrenheit and then it is the pure iron center of the earth which is 9000 degrees Fahrenheit and constantly has 45,000,000 pounds of pressure on it that’s 3,000,000 pounds more than the sea levels of pressure deference
If you live close or near a volcano or these unusual signs you and your
family should create an escape plan. Those includes and alert procedure, hospital and medical services for treatment, identification will be needed for out of area transport or driving. You also will need a means of transport, communication with family and friends, public warnings should be reviewed, a place for shelter if needed, and a type of rescue if trapped or hurt.
For your escape you will need to be aware of mudflows, landslides, acid rain, tsunamis, and earth quakes. It’s recommended to avoid rivers and low areas. Always wear long-sleeved shirts and long pants when warned about a volcanic eruption. Use goggles or eyeglasses to help protect you eyes from debris. Avoid running a car or truck engines if ash fall and driving during ash fall because of ruining you vehicle.
Scientists recommend going as far away from the volcano as possible. Try as hard as you can not to breath the volcanic dust. RZ5
This image is a cross section through the Earth showing the convection cells of the mantle. Ridge push happens at spreading centers where plates are moving apart. Slab pull happens at subduction zones where one plate is pulled down into the mantle.
Plates at our planet’s surface move because of the intense heat in the Earth’s core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down. As the cooled material sinks down, it is warmed and rises again.
Scientists once thought that Earth’s plates just surfed on top of the mantle’s giant convection cells, but now scientists believe that plates help themselves move instead of just surfing along. Just like convection cells, plates have warmer, thinner parts that are more likely to rise, and colder, denser parts that are more likely to sink.
New parts of a plate rise because they are warm and the plate is thin. As hot magma rises to the surface at spreading ridges and forms new crust, the new crust pushes the rest of a plate out of its way. This is called ridge push.
Old parts of a plate are likely to sink down into the mantle at subduction zones because they are colder and thicker than the warm mantle material underneath them. This is called slab pull.
Tectonic plats shape the earth by running in to each other and moving apart and sinking and floating up off the sea floor. When they crash together one goes under another and turns in to magma or they make mountains.
Some examples are like the Rocky Mts. or the Appellations.
“BBBOOOMMM!” you hear an explosion off in the distance then a wall of steaming hot water screams toward a house down in the valley below. The house is torn apart, but no one was in it lucky for you. You left for a trip and you were just coming home.
Lahars are a deadly mixture of volcanic debris and water, and it comes down mountains rushing up to 40 m/s. the family above was luck but not everyone is. Lahar is an Indonesian word made for the description above. It is also referred as a volcanic mudflow or debris flows. These dangerous freaks of nature can reach speeds up to 40 meters a second and 60 meters deep. It can carry from pebbles to large boulders 10 meters wide. The most surprising part is that the temperature varies widely and can reach 100 degrees centigrade.
They are formed by: 1) rapidly melting snow and ice by pyroclastic flows. 2) Intense rainfall on loose volcanic rock. 3) Breakout of a dammed area by volcanic deposits. 4) Debris avalanches.
Lahars are considered one of the most dangerous parts of a volcanic eruption increasing in size and speed as it flows down the mountainsides. They are similar to pyroclastic flows but contain 30% more water. Lahars that contain 20 to 60 percent more water tend to be more turbulent. Some that contain 80 percent more water flow more smoothly. But also can also have the consistency of concrete.
May 18 1980 Mount Saint Helens created a monster lahar that covered 24 square miles it destroyed 27 bridges and over 200 homes. It stranded 31 ships in up stream harbors in the Columbia River. It also decreased the depth of the river from 11 meters to 4 meters. Washington was devastated!!!!
As you see that lahars are very deadly and can boil you with scalding temperatures or smash you with giant pieces of rock. So please if you live by a volcano MOVE because if the ash or the lava doesn’t kill you the lahars will come pretty close. CM5
Lapilli are a small stone usually two to sixty four millimeters in size. It is made of solidified magma or resolidified rock, lapilli is expelled from a volcano and it usually between one half mile and one mile a lot of shapes of lapilli have been recorded some look like rain drops or buttons others look like a dumbbell or a sphere. The most common type of lapilli is a welded tuft. Lapilli also smell like sulfur, it looks a lot like rice. Lapilli travel least far because it is so small it does not catch the pressure of the explosion.
Volcanic ash is smaller than two millimeters in size, and it is made of solidified magma that has been crushed into a sand sized particle, and crushed rock. After an explosion the ash can go up to three miles away and leave a thick coating of as much as three feet of ash. A nickname for volcanic ash is tuft. Volcanic ash smells like sulfur and if a wind blows it hard enough it creates a yellow and grey haze that is almost impossible to see through.
So which way are you heading? You are heading towards the volcano because the ash falls farthest away from the volcano. And lapilli are only able to travel about one third of the distance as volcanic ash. RD05
The Richter scale graph is different the marcalli scale because it uses seismograms to record on a graph chart. On the graph it lines get bigger as the earthquake gets stronger. The scale assigns a single number to quantify the amount of seismic energy released by an earthquake. On a Mercalli scale it shows it by color. As the color gets warmer the intensity of the earthquake gets stronger. It quantifies the effects of the earthquake on earth’s surface, human objects of nature, and man made structures. The low degrees of the mm scales generally deal with the manner in which the earthquake is felt by people. The Richter scale was developed in 1935 by Charles Richter with Beno Guten Berg. The Marcalli scale was created by and Italian volcanologist Adolfo Cancani in 1945. The Richter scale can also record how many earthquakes there are in days, months, and even years. The Richter and Marcalli scale helps scientist figure out how much damage an earthquake can make. Even though they both help figure out how much damage earthquakes can make they are still different from the graphs they use and the technology. HLB5
Question: Explain how the movement of the tectonic plates shapes the earth using specific examples.
Response: There are many reasons why the earth is shaped why it is, but the two main reasons are heat and pressure. Heat is one of the leading causes of the formation of the earth. Heat helps form the earth by convection. Seawater, groundwater in the crust, and different magmas help convection. Most of the earths heat is generated from the decay of long-lived radioactive isotopes. As potassium, thorium, and uranium are concentrated in the upper continental crust, the heat produced by their decay accounts for 40% of the average continental heat flow.
The three main types of continental crusts are exposed continental shield (cratons), continental platforms, and mountain belts.
The ocean floor has many plates as well. The oceans crust tends to move away from mid-ocean ridges. Mid-ocean ridges transect the major basins of the world and are active sights for generating new crust from magmas rising from the mantle below from the linear fractures. The ocean floor is found at the ocean margins. Some of the known ocean rocks (oldest found) are only 200 million years old while most others are only 100 million years old. Some of the lowest heat flows are on old ocean floors and trenches, and in rapidly subsiding basins on the continental crust.
Pressure is another factor. The main pressure on the earth comes from the weight of overlying rocks and sub ducted plates. The standard unit for (Pa) is (1 atm=101 325Pa.). Mantle rocks have higher density, which further increases downward pressure.
This was a large earthquake with a massive magnitude of 8.6. This was a very serious situation and unplanned one too. The intensity was approximately 11. The depth was 18.6 miles set down by location program. The Felt report was enormous felt by almost everyone in the region. Nearly 1000 people were killed in the incident, 300 buildings destroyed in Nias. 100 people killed, many injured and several buildings damaged in Simeulue. 200 people were killed in Kepulauan Banyak. Only 3 people were killed along with 40 injured, and some damage in the Meulaboh area, Sumatra. A 3-meter tsunami damaged the port and airport on Simeulue. Tsunami runup heights as high as 2 meters were observed on the west coast of Nias and 1 meter at Singkil and Meulaboh, Sumatra. At least 10 people were killed during evacuation of the coast of Sri Lanka. Felt with an intensity of 4 along the west coast of Malaysia. There was also an intensity of 4 felt at Bangkok and 3 at Phuket, Thialand. A 3 was felt at Singapore, and a 3 at Male, Maldives. The quake was also felt in the Andaman and Nicobar Islands, India and in Sri Lanka. Tsunami wave heights were recorded from selected tide stations: about 40 cm on Panjang, Indonesia and about 25 cm at Colombo, Sri Lanka; 40 cm on Hanimadu, 18 cm at Male and 10 cm at Gan, Maldives. Initial observations indicate about 1 meter of subsidence on the coast of Kepulauan Banyak as well as 1 meter was uplifted on the coast of Simeulue. Seiches were observed on ponds in West Bengal, and as well as India.
In Conclusion, You can never be too careful, so always have a safe plan to use if you get stuck in the middle of an earthquake, because it is better to be safe than sorry.
The tiltmeter works in a very unique way. The modern and new electric tiltmeter is slowly replacing the old and not precise tiltmeters. This new instrument uses a simple bubble-level principle. This works because an arrangement of electrodes senses the exact position of the bubble in the electrolytic solution. The precision of this machine is dead on. If the land has any horizontal change, this tiltmeter will catch it. It uses a data logger to keep track of the movement. This new design is really insensitive to temperature so if it is cold or warm your chances of getting the right data are great. Some tiltmeters that are not up to date, but are a little useful for normal people is the long-tube tiltmeter. This consists of two pots and a tube and some water. Any change in tilt would be registered by a difference in fill-mark of one pot compared to the other. A tiltmeter measures horizontal tilt in the land. That’s how it gets its name. It is useful in structures because it measures the slightest tilt so if a building was slowly tilting, people would be notified so no damage would be done. This instrument is useful to scientists because it can help predict earthquakes. They can study what happens before, during, and after the earthquake, it can also tell if the land is slowly tilting or moving. This is how a tiltmeter works, measures, and is useful to scientists.
The tilmeter is a very useful instrument to a lot of people. It can help modern day people and high tech scientists. Maybe someday it will help by using all of its data and predict when earthquakes will happen. Know you know how a tiltmeter works, what it measures, and how it helps scientists. Maybe someday you will use this instrument in the future.
You might ask how did the plates form mountains by pushing into one another? Well how it worked was the Indo-Australian plate was forced under the Eurasian plate and pushed molten rock other words know as magma and forced it up-ward. This is known as a subduction zone. Only a portion of the Himalayans were formed by this subduction zone due to the Indo-Australian plate had high counts of enormous quantity of light quartz-rich rocks which the Eurasian plate also had. When these parts of the plates hit one another they sky rocketed which formed what is what modern day Himalayan mountain range.
Mount Everest is one particular mountain in the Himalayan mountain range because it is the largest mountain in the world (above sea level). This mountain was one that was formed from the plate collision when the plates pushed one another up (rather than subducting). Scientists believe that the mountain is growing 1 cm per year due to the Indo-Australian plate stretching.
The Himalayan mountain range was formed in these five stages.
One the Indo-Australian plate moved northward towards the Eurasian plate. This is believed to happed from the convection inside the mantle of the earth. The second stage of the formation of the Himalayan mountain range is the collision of the plates, which was the start of the next two stages. The third stage was when the plates subducted and force the magma up. Fourth was when the plates hit light quartz-rich area of the plates colliding. And finally, fifth, the indo plate continues to stretch and compress into the Eurasian plate. So how the Himalayan mountain range was formed all was started with tectonic plate movement.
The Richter scale measures magnitude, which is calculated by the height of the earthquakes waves measured by a seismograph. Magnitude is almost always measured on the Richter scale. The points 1-9 of the Richter scale corresponds to a factor of 10 increase in the amplitude of earthquakes waves.
Another scale used to describe the size of earthquakes shows the intensity of quakes based on eyewitness descriptions of the damage in the area. This scales used roman numerals from I~XII and is called the modified mercali scale.
As you can see the two scales are very different and if an earthquake happens near my home I would rather be informed of the damage done than just a simple number of intensity. This would help me prepare for what I would find as far as damage to roads, building and my city but the intensity will vary depending upon the place from which it was measured.(EE4)
On December 26th 2004, at 00:58:53 UTC, an undersea earthquake occurred off the coast of Sumatra Indonesia (3.316N, 95.854E). The quake had a magnitude of around a 9.2, it was the second largest earthquake recorded on a seismograph. It also had the longest duration of faulting ever observed, between 8.3 and 10 minutes. 26.3 megatons of TNT were released during the quake, causing the entire planet to move 1 centimeter (0.5 inches). An estimated 1,600 km of fault line slipped about 15km at the subduction zone along where the Indian plate and Burma plate collide (the Indian plate is sliding under the Burma plate). This earthquake triggered devastating tsunamis along the coasts’ of most of the landmasses bordering the Indian Ocean. The countries affected the most were Indonesia, Sri Lanka, India, and Thailand. With waves up to 30 meters (100 feet), killing an estimated 225,000 people, in eleven separate countries, 1,126,900 people displaced, 229,866 people lost, and inundating costal communities. This earthquake trigger several other earthquakes around the world some as far as Alaska. Its safe to say this was one powerful quake.
No matter how sad and tragic this event was we cannot forget what happen on the December 26th 2004, since that day earthquake predictors have been set up all around the fault lines so that, if ever another huge quake occurs we can maybe react faster and get people to a safe place as soon as possible.
by mmb 4th hour
The island chain curves around, so Loihi will most likley end up southwest of the big island. Volcanic activity could move around and based on plate activity, coud shift its position. The pattern of volcanic eruptions has some part in the movement of the islands. the youngest islands are to the south and the current volcanic activity could cause the island chain to shift northwest causing Loihi to migrate from its current position to its estimated position.
The volcanic activity causes earthquakes which are shifting the plates and causing the islands to shift.
whwn Loihi erupts it forms carters and dumps sediment on the sea floor that is shifted by the earthquakes that follow. The last volcanic and earthquake activity occurred in 1996 and greatly changed the shape and shifted the plate that runs from the southeast to the northwest of the Hawaiian Island chain.
Another theory is that there is an immobile hotspot under the plate that the south eastern islands of Hawaii are located on. AS the molten rock hits the surface it cools pushing existing rock formations northwest along the ridge of the plate. It has been estimated that the narrow vertical passageways are about 200 miles across that feed the molten lava to the surface or into long narrow lava tubes near the surface. All this activity causes a painfuly slow chang in the Hawaiian Island chains location. ~na4
To prepare for an earthquake in your home you will need to go through the following steps. First you will need to take many safety precautions and preparations. Then you will need to follow through and make a plan when an earthquake actually occurs. In order to stay safe follow the step in this announcement.
While preparing for an earthquake you will need to go through the following steps. Step one is to bolt your house to its foundation. Next you will need to go to a red cross class on first aid incase of an emergency. Next you will need to teach all of your children the Drop, cover and hold on. This technique is for your safety and wellbeing. Next you will need to make a supply of food in your house. You will also need to learn how to use a fire extinguisher. You will also need to inform babysitters on your plan. To prepare your furniture you will need to bolt furniture to the wall studs. Install strong latches to shelves, and strapping the water heater to the wall. With these steps you can prepare your house for even the biggest earthquake.
Once shaking occurs you will need to go through with many preparations. Once shaking starts drop, cover and hold on. Crawl to a strong desk or table to get under it. Only move a few steps. If you are sleeping in bed and shaking starts take the pillow and cover your head and face. If out of a building go away from a building and power lines.
Over all earthquake preparations may take a long time but is definitely worth it. Making a plan and following the steps during an earthquake is also needed. You will also need to inform any visitors in your house about your plan.
The crust is the first layer of the earth and is made up of two types of crust, oceanic and continental crust. Oceanic crust is below the oceans. There the crust is 4-7 miles thick. The rocks of the oceanic crust are very young compared with the rocks of the continental crust. The rocks of the oceanic crust are not older than 200 million years. The material of which the oceanic crust consists is for the greater part basalt. Basalt has a dark, fine and gritty volcanic structure. It is formed out of very liquid lava, which cools off quickly. The earth's crust is the thickest below the continents, with an average of about 20 to 25 miles and with a maximum of 45 miles. The continental crust is older than the oceanic crust; some rocks are 3.8 billion years old. The continental crust mainly consists of igneous rocks and is divided into two layers. The upper part mainly consists of granite rocks, while the lower part consists of basalt and diorite. Granite is lightly colored, coarse-grain, magma. Diorite has the same composition, but it's scarcer than granite and is probably formed by impurities in the granite-magma.
The layer above the core is the mantle. It begins about 6 miles below the oceanic crust and about 20 miles below the continental crust. It is about 1,800 miles thick and makes up nearly 80 percent of the Earth's total volume. Science deals with the structure of the mantle in two different ways. One way is based on its chemical construction, the other on the way layers stream or move. The mantle is made up of asthenoshere and the lithosphere. The tough liquid part of the outer mantle is the asthenosphere. The lithosphere is the stiffer part of the outer mantle and the crust. The lithosphere 'floats' on the asthenosphere, like ice on water.
The center part of the earth is the core. This part of the earth is about 1,800 miles below the earth's surface. The core is a dense ball of the elements iron and nickel. It is divided into two layers, the inner core and the outer core. The inner core is solid and about 780 miles thick. The outer core is so hot that the metal is always molten, but the inner core pressures are so great that it cannot melt, even though temperatures there reach 6700ºF.The outer core is about 1,370 miles thick. Because the earth rotates, the outer core spins around the inner core and that causes the earth's magnetism.
The journey through the earth is made up of four different layers with different characteristics about them to make them different from each other. The four different layers include the crust, mantle, and the core that is divided into two parts or layers the outer and inner core.
San Francisco in 1906 was the largest and most important port on the pacific coast, and the ninth largest city in the United States and it had the largest china town outside of Asia. The population of this large city at the time was only 400,000.
On April 18 1906 people were still sleeping and some were just waking up around 5:00 am. But at 5:12 am the ground began to violently shake beneath them and outside their windows buildings were falling down. The shaking lasted around 45 to 60 seconds. This massive earthquake was so large that it was felt in Oregon to Los Angeles and inland as far as central Nevada. Rupturing the north most 296 miles of the San Andréas fault from northwest of San Juan Batista to the triple junction at Cape Mendocino, the earthquake confounded geologists with its large horizontal rupture length. The earthquake estimated at approximately 8.25 on the later developed Richter scale.
The great fire that burned after the earthquake had caused most of the damage in the city. The fire burned for four long days and burned most of the remaining buildings.
The earthquake and fire left 3/4 of the population homeless. Over 3000 deaths were caused directly or indirectly by the catastrophe at. 498 deaths were reported in San Franscisco.64 in Santa Rosa, and 102 in and or near San Jose. The death toll rose to 3000 because many were shot when mayor Eugene Schmitz ordered police and army personnel to shoot looters.
In conclusion the great San Francisco earthquake of 1906 was one of the most largest and devastating earthquakes of all time and is a big part in U.S. history.
Tiltmeters work by measuring small changes in the ground. The very first tiltmeter was a long-length stationary pendulum. These were used in the very first large concrete dams, and are still in use today, amplified with newer technology such as laser reflectors. Although they had been used for applications such as volcano monitoring, they have distinct disadvantages, such as their huge length and sensitivity to air currents. Even in dams, they are slowly being replaced by the modern electronics tiltmeter.
Volcano and earth-movement monitoring then used he water tube, a long baseline tiltmeter. This was a simple arrangement of two water pots, connected by long water filled tube. Any change in tilt would be caused by a difference in fill-mark of one pot compared to the other.
Although extremely used throughout the world for earth science research, they have proven to be quiet difficult to operate. For example, due to their high sensitivity to temperature differentials, these always have to be read in the middle of the night.
The modern electronic tiltmeter, which is slowly replacing all other forms of tiltmeter, uses a simple bubble-level principle, as used in the common carpenter level. An arrangement of electrodes senses the exact position o the bubble in the electrolytic solution, to a high degree of precision. Any small changes in the level are recorded using a standard data logger. This is quiet insensitive to temperature, and can be fully compensated, using built-in thermal electronics. A newer technology uses MEMS electronics, it is not known if this can eventually displace the common bubble.
The most dramatic application of tiltmeters is in the area of volcanic eruption prediction. The main volcano in Hawaii had a habit of filling the main chamber with magma, and then discharging to a side vent. This repeated action, with a pattern of swelling of the main chamber, draining of that chamber, and then an eruption of the adjoining vent. Each number at the park of tilt, on the graph is a recorded eruption.
Seismometers are an important part of the volcanologist’s arsenal. Small earthquakes often occur when magma pushes its way to the surface, and this handy tool will pick these up and record them. The earthquakes generally become more frequent and larger as the magma gets closer to the surface.
The tiltmeter is directly attached to the volcano. It measures small changes in the slope of the volcano, using a conducting fluid and a bubble, much like a carpenter’s level. When the bubble moves, the electrodes in the conducting fluid give off a voltage that the tiltmeter reads.
Volcanologists have the relatively new method of being able to use satellites to read the heat of volcanoes then send it to them digitally. Recording infrared radiation shows the heat and coolness as different colors will show whether a volcano is heating up for an eruption.
Another thing scientists look for when monitoring volcanoes is the amount and type of gasses emitted from it. When near to eruption, gasses become more pronounced and obvious. But, gasses sometimes are trapped by fast cooling lava and don’t come to the surface. Then the scientists cant tell if the gasses are more pronounced. Also, the gasses are hard to collect, seeing as they are extremely poisonous and need to be collected at the top of the active volcano.
Using these tools and methods, scientists are able to help people near possibly active volcanoes. When the seismograph shows signs of a major increase of seismic activity, when the tiltmeter detects changes in the surface of the volcano, when satellites find the volcano is heating up, and if gasses coming out of the volcano become more pronounced, then scientists know that the volcano is charging up for a blast that could kill thousands. Then they can evacuate the area and save those lives. That is the way scientists stand up to volcanoes and predict the next eruption.
On July 17, 2006, the west coast of Java was it by a 3-meter high tsunami. The water reached an astonishing 200 yards inland, destroying all houses, restaurants, and hotels that stood in its path. The tsunami was created from a 7.7 magnitude earthquake, whose epicenter was approximately 150 miles from Java’s coastline. However, this Indonesian island is quite familiar to tsunamis, considering it was hit by the 2004 tsunami that had a whopping 9.3 magnitude! Now don’t worry folks, this type of destruction will probably never happen to you. That is, unless you live on an island on top of the pacific ocean’s “Ring of Fire” plate boundary, where Java is located.
Now as you can imagine, this type of natural disaster doesn’t just leave people unharmed. The total number of confirmed deaths caused by the Java tsunami is 547, while 595 were left injured. If that wasn’t enough, 54, 256 people were displaced. Most people harmed were from the Pangandaran Beach, where many tourists and locals stayed. Because so many people were tourists, they did not know how to evacuate very well.
Other than tourists, there is another, much larger, reason so many people died or were injured. The State Minister of Research and Technology received bulletins warning about the tsunami expected to hit in 45 minutes. However, he did not post these bulletins because he didn’t want to start an “unnecessary alarm”. Perhaps he did not expect suck a dangerous tsunami with an intensity of III-IV. He also wasn’t prepared for the 22 aftershocks that followed the tsunami/ earthquake.
As you can see, this Java earthquake/ tsunami was dangerous and deadly. I hope you have learned more about the location, the injured, and some other facts to help you understand how much of an impact this disaster made.
Scientists don’t know when earthquakes are going to happen but they do try to predict them. They use seismographs and just the movements of the volcano like ash, magma, bulges, and gas coming out. All though they don’t know exactly when it’s going to explode there has been many advances in technology to move forward. It would help to know when the eruption is going to happen so they can recommend an evacuation of the area in time so no one gets hurt.
One way to predict eruptions is a seismograph. A seismograph is a sensor that detects the intensity of the earthquake by the moving magma. The seismograph can help detect when it’s coming because the magma moves faster. Sometimes volcanoes spit out magma a little bit at a time and eventually keep getting more and more until it explodes. This gives scientist time to give an estimate when to evacuate. When ash and steam come out they now its getting ready to erupt. Scientists use land set satellite to see how much gas the volcano is producing everyday. Some volcanoes have bulges that they grow with magma inside of them. These are some ways to predict volcanic eruptions.
Each and every volcano is different so there is no set time to evacuate. Volcanoes can simmer and bubble for hours, days, weeks, months, and even years without erupting. Scientists recommend an evacuation depending on the density of the population, degree of mobility, and transportation factor. If there are many people in the area they take it more serious and recommend an evacuation sooner. The mobility and transportation is also a huge deal because they have to have it to get away. When scientists recommend an evacuation they need to make sure there is enough transportation to get everyone out in time. That’s why a recommended evacuation on time is so important to people and scientists.
These are some clues to predicting eruptions and how advances in technology are helping. With these clues they can better recommend an evacuation in time to save peoples life. That’s why this is so important to know.
Seismologists use a Magnitude scale to express the seismic energy released by each earthquake. Here are the typical effects of earthquakes in various magnitude ranges. Seismology a scale of seismic intensity is a way of measuring or rating the effects of an earthquake at different sites. The Modified Mercalli Intensity Scale is commonly used in the United States by seismologists seeking information on the severity of earthquake effects. Intensity ratings are expressed as Roman numerals between I at the low end and XII at the high end.
The Richter scale is the best-known scale for measuring the magnitude of earthquakes. The magnitude value is proportional to the logarithm of the amplitude of the strongest wave during an earthquake. A recording of 7, for example, indicates a disturbance with ground motion 10 times as large as a recording of 6. The energy released by an earthquake increases by a factor of 30 for every unit increase in the Richter scale. The table below gives the frequency of earthquakes and the effects of the earthquakes based on this scale.
The intensity of an earthquake at a particular locality is a measure of the violence of earth motion produced there by the earthquake. It is determined from reported effects of the tremor on human beings, furniture, buildings, geological structure etc. Unlike the magnitude, which has a unique value for a particular earthquake, the intensity of an earthquake at a place depends on the distance of that place from the epicenter, the depth of the focus, the intervening and local earth structures and the type of fault motion that caused the earthquake.
Loihi is a submarine Hawaiian volcano the might grow to form a new island. Loihi seamount, sometimes known as the "youngest volcano" in the Hawaiian chain, is an undersea mountain rising more than 3000 meters above the floor of the Pacific Ocean. Loihi sits submerged in the Pacific off of the south-eastern coast of the Big Island of Hawaii. This certain submarine volcano was made by hot spots. What are Hot Spots? Hot Spots are where hot magma currents rises from deep in the earths crust. The way that the Loihi submarine volcano is moving is either to the north or to the northwestern. Researchers think that the loihi submarine volcano will either make it to the surface in either 100 years or to even 50,000 year or that it might not even make it to the surface at all.
When there is too much pressure from a Hot Spot in the earths crust it will erupt which is just like a volcanic eruption. Which then when all the volcanic ash and depre is let out it will repeat this process for a long period of time. When there is a new volcanic island forming usually how it started was from a volcanic eruption or from hot spots. When and if there is a new volcano to formed I would think that it would either form at a hot spot. One reason for that is because most volcanoes are formed by and or on a hot spot. But not all volcanoes are formed on hot spots they can also be formed at the ring of fire where almost half of earthquakes are formed. the way that its being formed (Loihi) is that hot spots pressure is building up and its starting to move this submarine volcano up to earths crust/surface.
In the end the way that Loihi was formed is from the hot spots in the earths surface/crust. And if there was ever a new Volcano to be formed it would either be on a hot spot or in the ring of fire!
There are many possible ways that Lahars can form, but one of the most common reason is because of a volcanic eruption. A volcanic eruption can cause more that one Lahar at once. The extreme heat coming from the volcano can rapidly melt snow and ice on the top of a volcano, rejecting water from a crater lake. Most of the time, lahars are formed because of intense rainfall after an eruption. Rainwater can easily erode loose volcanic rock/soil from hillsides and in river valleys. Many of the largest lahars begin as landslides of saturated and hydrothermaly altered rock on nearby and adjacent hillsides of a volcano.
Lahars almost always appear near stratovolcanoes. These volcanoes usually erupt explosively and their tall, steep cones are covered with snow or topped with a crater lake. Which is a place on the volcano where it is constructed of weakly consolidated rock that is easily eroded or internally weakened. Lahars are also common around that snow and ice covered shield volcanoes where eruptions blast fluid lava frequently on top of glaciers. One example of this would be the volcano at Vatnajokull, Iceland.
Lahar is made of debris from avalanches, pyroclastic flows that dilute themselves in river water as they travel down slopes, natural dam failure and rain fall on loose material such as ash. Lahars that contain twenty to sixty percent sediment are usually very turbulent and con carry large boulders up to tem meters in diameter. Lahars that contain more that eighty percent sediment usually flow smoother and much faster than their turbulent partner; these lahars can pick up rock to the size of ten meters in diameter.
An example of a deadly lahar is the Nevado del Ruiz stratovolcano, which is near the Andes Mountains in South America. Over the years, this volcano has produced many lahars and has killed over twenty thousand people. On November 13, 1985, this volcano violently erupted and formed a large lahar in the Guali river valley. Many towns were destroyed in this lahar and more that 23,000 people were killed.
Lahars are very deadly and there is not a way to prevent them. lahars are very deadly and many people die each year.
In conclusion, there are many differences between the Richtor and the Mercalli scale. The differences I have explained above prove my reasoning.
Today, scientist can predict eruptions. I have been studying about the ways scientist predict so many eruptions now in days. Scientist use installing tilt meters near the dome is critical. Tilt meter detect increasing rates of deformation before eruption heavy ash balls.
A tilt meter is an instrument designed to measure very small changes from the horizontal level, either on the ground or in structure. Another term for the tilt meter is inclinometer. Some of the volcanoes signs are the number and size of earthquakes increase in and around the volcano. The ground deforms or "bulges" at the eruption site. A lot more gas comes out of the volcano. They also use seismometer to predict eruptions. Seismometer is a sensor that detects the intensity of an earthquake. Scientist would recommend evacuation of an area based on these clues when they get notice of a volcano eruption. Scientist are studying the deposits left behind. In that way they can make predictions. Before an eruption, magma moves into the area beneath the volcano and collects in a magma chamber, or reservoir. These are some clues I’ve found. There are more clues to how scientist make predictions of eruptions.GC
Lahar is like concrete, its wet and muddy when it’s moving and hardens when stopped. Lahars can be huge. The Osceola lahar produced 5,600 years ago by Mount Rainier in Washington produced a ton of mud 460 ft deep in the White River canyon and extends over an area of over 130 sq mi for a total volume of 0.55 cubic miles.
Lahars usually travel down valleys. They have a wide range of velocities from 1 m/s to 40 m/s. The speed of a lahar depends on the channel width, channel slope, volume of the flow, and grain size composition. Lahars can travel long distances. Some lahars have traveled hundreds of kilometers from their source. The deposits of a lahar that traveled 60 km from its source at Mount Rainier can be found near the large city of Seattle, Washington. The lahar's origin at Mount Rainier helped make that volcano a decade volcano.
Lahars have been known to transport very large boulders. At Mount Pinatubo, boulders measuring 1.5 m long were not uncommon in lahar deposits. The lahars from Nevado del Ruiz transported a boulder that was 208 cubic meters, 300 m downstream.
When a lahar travels down valley, the high point of the lahar is usually marked by the mudline it leaves on trees, valley walls, and buildings. This mudline marks the upper limit of how high a lahar will go. This upper limit is important because it defines how high people must go to be out of danger from the lahar. The small eruption of Nevado del Ruiz in 1987 produced large lahars that destroyed the city of Armero. Unfortunately, the 30,000 people who lost their lives might have been saved had they established an appropriate line of communication and evacuated to higher ground. If you live in the mountains you should be safe but if the mountain is volcanic I can’t believe you still live there.
One thing that scientist use to predict volcanic eruptions is a Tiltmeter. Scientists use tiltmeters to detect increasing rates of deformation in a mountain before an eruption. What a tiltmeter does is measure the tilt or slop of the entire mountain. This provides additional information about the volcano and the magma inside it. Another thing that scientists will use is a seismometer. A seismometer is used to try and pinpoint an earthquake, which also tracks the rise of magma and its movement along fissures. There are also quite a few signs of a volcanic eruption that a scientist can use to tell if there is going to be an eruption. Some of the signs are, sulfurous odors, steam puffs coming out from cracks, restless and fleeing animals, dimming of the sun in mid-day, earth tremors, and changes in weather. These are things that almost anyone could notice. One last big thing that can help predict when a volcanic eruption is going to occur is a correlation spectrometer. A spectrometer can measure the amounts of sulfur dioxide that the volcano is letting out. Sulfur dioxide is a telltale gas that is released in increasing amounts before an eruption.
So in conclusion there are a few ways to predict volcanoes but in the end it is hard to actually tell when every volcanic eruption is going to occur. Volcanoes are very interesting things and really have no particular pattern to when they will erupt.
3. Gregory vogt, predicting volcanic eruptions
First choose a safe place in every room, like somewhere where nothing can fall on you like under a desk or table. Practice drop, cover, and hold on a couple times a year. Drop under a desk or table, hold on and protect your head by putting your arms over your head. If there is no table or desk around, sit on the floor against an interior wall where nothing can fall on you. Teach children to drop, cover, and hold on too. You could go to a family or friends house that live out of town. You can talk to a professional to find out more ways to protect your home. Take a first aid class and keep your training up to date. If you need to use a fire extinguisher, get training on how to use on first. Tell your babysitters or caretakers about your plan so they know what to do too. Prepare a kit of supplies for your home and car. In the kit you should include a first aid kit, food water, extra clothes, a battery powered radio, a flashlight, and extra batteries.
Now that you have your plan, I'm going to tell you what to do if an earthquake happens in different situations. If you are in bed, hold on and stay there and cover your head with a pillow. If you are outdoors, find a clear spot away from buildings, trees, and power lines. Stay on the ground until shaking stops. If you are in a car find a clear spot and stop. Stay there until shaking stops. I hope this helps you and your family make an earthquake plan and be prepared for one.
But it didn’t stop at that; there were also extensive amounts of damage. At least 32,335 buildings collapsed in Anantnag, Baramula, and Jammu. And other buildings were collapsed in Abbottabad, Gujjranwala, and Islamabad, the capital of Pakistan. Over 4 million people were left homeless. Imagine that, your home being destroyed in a matter of seconds. Sad right? Then rock falls and landslides destroyed several mountain roads and highways. This cut off access to the area for many days. The heaviest damage though, happened in the Muzaffarabad area. And nearby by in the town of Uri, 80% of the town was destroyed. Then in Kashmir, entire villages were destroyed. Liquefaction and sand blows in the western part of Vales of Kashmir and near Jammu hit. Also, there were many landslides and rock falls in parts of Himachal Pradesh, India. As you can see this earthquake caused a lot of damage to this part of Asia. Well, on the up side, at least it’s not like this turned out like the Great Tokyo Earthquake where about 100, 000 people were killed. In short the Pakistan earthquake was very devastating for the area.
You are laying in bed on a summer night, when all of a sudden you start to shake. You hear your children screaming, and furniture starts shaking and moving. Lamps are being knocked off the nightstand, paintings, and mirrors are coming off the wall.
What would you do when an earthquake hits your house, do you know the steps to take to quake proof your house, what to tell your children to do to keep them safe during an earthquake? If your answers were no to any of those questions you should follow these steps below to safer way of living.
Steps for earthquake preparation and safety
1. Identify the potential hazards in your home and begin to fix them, example your gas line breaks and you have a leak, which could lead to a potential explosion.
2. Create a disaster supplies kit, including a few flashlights, water batteries band-aids, a crow bar, a pocketknife.
3. Create a disaster-preparedness plan with your family, tell your children in case of an emergency have a flashlight under your bed with a pair of shoes, take your mattress (if the child is old enough) and to take it over there entire body to protect from any objects that my fall off the walls or glass that may break. Tell them to start yelling, “I am here” after all the shaking stops, and to not move until some one finds them.
4. Identify your buildings weaknesses, and begin to fix them. Example makes sure the walls, and the roof is sturdy.
5. Protect yourself during an earthquake. Drop, Cover, Hold On.
6. After the earthquake check for damage and injuries.
7. When safe follow your plan and get to your emergency earthquake kit, and make sure every one in the house that was not able to get out by them selves was told their name to the search and rescue team.
Hopefully this information is very useful to you before and after an earthquake. Also her is some more information that may be helpful for you before an earthquake.
Remember to secure all heavy furnishings, and keep all large, and heavy objects in the lower cabinets. Make sure that if your house was built after 1935 you get it check for any possible danger. Some more preparations are to make sure you know how to shut off the gas, water, and the electricity. Last make sure you have emergency foods, and water.
Hopefully this information will help you. Knowing the steps to be prepared and safe during an earthquake are the most important, so stay covered stay still, and hold on.
While the Richter scale measures the magnitude of the quake. To do this you have to have a seismograph to measure the shaking that goes on during the quake. It usually measures the activity underground. The magnitude of an earthquake can go to any height. And for every level of magnitude the scale increases by a force of thirty-one times that of a magnitude a full level below it. Unlike the Mercalli scale this way of telling how much shaking went on it has no upper limit to how much shaking can occur, even though the highest ever recorded was an 8.9 magnitude.
On the other side the Mercalli scale measures the amount of damage caused by the shaking. There are twelve levels that this can have ranging from barely noticeable to waking people up and even to knocking buildings down. While the Richter scale is a mathematical thing the Mercalli is only based on what it looks like not how much shaking actually occurs. This has a bad side that most of the levels are pretty much the same. The levels are blurred also not being very clear.
The only other difference is how they are measured. The Richter has a very precise way of measuring it. While the Mercalli is pretty much just how bad it looks not how bad it actually is.
Lahar is an Indonesian word that describes a mudflow or water saturated debris. Geologists use that word to describe it. When moving lahars look very similar to masses of wet concrete carrying pieces of rock debris. Volcanic eruptions, glacial melting, and sector collapse form lahars. Lahars can also develop from earthquakes, steam explosions, and intense rainstorms. They are powerful forces able to carry large debris pieces for long distances at a time. They are highly common of stratovolcanoes.
Lahars can cause great amounts of damage. They are capable of moving house size boulders and trees. Developed regions at the bottom of volcanoes are in extreme danger to lahars. They include steam explosions and intense rainstorms; Mount Rainier’s steep slopes make lahars extremely dangerous to that area.
One lahar occurred in Nevado del Ruiz in Colombia. It had dangerous glacial gaps. It was dangerous because it had a long history of lahars in the area. Nevado del Ruiz released a lahar on September 13, 1985. It was triggered by an intense glacial outburst and a small eruption on September 12, 1985. It traveled at a high speed of 30 kilometers per hour. It raced down the Azufrado River Valley and buried a town. The town of Armero was buried and so were about 24,000 of its residents.
Lahars are greatly dangerous and difficult to predict. The threat of lahars are still there. Lahar eruptions in history prove how destructive lahars can be.
On August 18th, 1906, every living being in the San Francisco area thought their day would be like any other. However, early in the morning at 5:12 am local time, foreshocks, or minor tremors of shaking, occurred. The actual earthquake struck approximately twenty to twenty-five seconds later. With a rating of VII to IX on the Mercalli Scale. The epicenter of the monster earthquake was located near San Francisco. Violent shakings occurred also, punctuating the strong shaking which lasted forty-five to sixty seconds. This giant earthquake was felt from southern Oregon to south Los Angeles and inland as far as Central Nevada. It ruptured the northernmost 296 miles of the San Andreas Fault. Geologists were confounded by the earthquake’s large horizontal displacements and great rupture length.
After analyzing the displacements and strain in the areas surrounding San Francisco, a young geologist named Reid, formulated his theory on elastic-rebound. This theory has been the foundation of our knowledge of earthquakes, and the principal model of the earthquake cycle, ever since he discovered it. Since his discovery, earthquakes are easier to predict. They are still very unpredictable, but not as much as they were in the early 1900’s.
Ever since the earthquake known all over the world as the great San Francisco earthquake, geologists have found new ways to protect houses and other buildings from as much damage that occurred in 1906. This damage included buildings in ruins on the cracked, uneven surface, power lines down and causing fires all over surrounding areas. The earthquake was indeed very tragic, but it changed all geologists’ theories of earthquakes today, and has even saved multiple people’s lives.
Thursday, March 13, 2008
It all started at 5:12am April 18 1906. There was a huge foreshock that could be felt
throughout the San Francisco area. Everyone knew that this would be an earthquake that
would be remembered for a long time. 25 seconds later the earthquake started. This was a
huge earthquake! Buildings were shaking violently, and people were scared out of their
minds. It was a 7.8 on the mericali scale. It could be felt from south Los Angeles, to
southern Oregon, and as far inland as Nevada. The earthquake lasted for a whole 60
seconds. After the earthquake ended, the whole city was in ruins. Buildings were
collapsed, and houses were destroyed. But then the worst thing that could have possibly
happen, happened! Numerous buildings were in fire! Everything you could see was up in
flames. The firefighters tried to use dynamite to stop the fire from spreading to more
buildings. This did not work at all, in fact in made everything even worse. This actually
made more fire. And while the buildings were being blown up, all the survivors were
standing there watching. And they still had bricks back then, so all the bricks came
crashing down on all the people. Many people and all the horses carrying the people were
killed. But in the earthquake, all the water lines were broken, so they had no way to put all the fires out. 798 people died in the flames and earthquake. But then the military took
over. They were ordered to shoot and kill any looters, or anyone committing a crime. 500
more people were shot and killed. The total property damages, cost 400 million dollars.The military brought all the survivors by wagon, to a camp, where they would be cared for and have shelter. In conclusion, the earthquake of 1906 was a devastating hit on everyone in San Francisco.
Today, in this century there are many active volcanos that spread worldwide.
A- Scientists can often find clues about past eruptions by studying the deposits left behind. Areas affected by lava flows, debris flows, tephra, or pyroclastic flows can be mapped, making disaster planning more effective. In addition to this type of long-range forecasting, scientists are becoming more and more skilled at spotting the warning signs of an eruption.
- seismic disturbances
- ground will shake sort of like an earthquake
- sulfur dioxide levals will increase by a lot
- the animal and birds movement will be somewhat strange
- the volcanos slope will swell and possibly change
- earthquakes will occur
- the seismic activity of an recent eruption might set off a near by volcano
- the ground will swell which will push magma to the surface
Q- Are there any warning signs of an eruption?
A- Before an eruption, magma moves into the area beneath the volcano and collects in a magma chamber, or reservoir. As it comes closer to the surface, the magma releases gases. These events can offer valuable clues about the likelihood of an eruption.
The problem with predicting volcanos is Volcanologists (people who study volcanos) are becoming very skilled at predicting an eruption. Still, It's very difficult to pinpoint exactly when an eruption will happen. Most of the time moving magma doesn't result in an eruption, but instead cools below the surface. With many volcanoes erupting only every few hundred years or maybe even a few thousand years, it's not possible to monitor every site. However, Volcanic eruptions don't occur without warning. If there are monitoring devices set up, Volcanologists should not be caught off guard by disastrous eruptions.
Preparation and Evacuation
When a volcano comes to life, a few weeks may not be enough time to prevent a tragedy. Planning is the key to saving lives. People must be educated about volcanos and their volcanic hazards. Evacuation plans must be in place. Communication between scientists, the media and the public should be practiced. Emergency measures must be thought out and agreed upon.
There are four ways to cope with volcanic hazards.
- Volcanologists can try to keep the hazard from occurring which is a very diffacult task.
- Try to change its path or reduce its impact on existing development.
- Take steps to protect future development.
- Do their best to have disaster response plans
Obviously, there is no way to stop an eruption. Although volcanologists can attempt to reduce the eruption's effects by reinforcing structures such as strengthening roofs to support the weight of tephra deposits or by building protective works such as walls to deflect lava flows away from developed areas. Such efforts can be and have been successful, but are of limited.
One satellite is GPS. GPS is short for Global Positioning System. GPS can determine the region of geological structure, volcanic eruption. It can pin-point ground movement and monitor crust deformation. Scientist put sensors next to plate boundaries which detect movement. GPS is known to be used in cars and for traveling, but it has major uses when it comes to tectonic plate motion.
Another satellite system is SLR. SLR means Satellite Laser Ranging. It uses an absolute reference system for measurements of post glacial rebound, and temporal mass distribution determination of solid Earth and ocean. SLR uses laser to range satellite. The satellite sends back measurements. As time passes, and plates move, the satellites measure the movement of the plates. SLR is frequently used to track plate motion.
The last satellite system is inferometry. There two types of inferometry, VLBI and SAR. VLBI stands for Very Long Baseline Inferometry. VLBI uses satellite in space monitor ground motion. VLBI is capable of determining vertical and horizontal displacements in the surface. SAR is the second type of inferometry. SAR stands for Synthetic Aperture Radar. SAR involves taking pictures of a part of the Earth’s surface. The measurements are so precise that slight movements can be detected.
Scientists use satellite systems to detect plate motion. Some are GPS, SLR and inferometry. These are very strong machineries. They can detect small movements on the Earth’s.
Do you know what a Lahar is? Well it took some research, but now I know what it is. Lahar is a deadly type of mudflow which is composed of what is similar to pyroclastic material. Lahars also contain water that flows from a volcano. Some information that I will tell you about, is when and where lahars have been located, specific details about Lahars, and many ways that Lahars are formed.
Some specific places of where lahars have been located are in New Zealand. In NewZealand, Mount Ruapehu they had to set up a warning system and later had success after it alerted officials. This happened On March 18, 2007. The New Zealand Conservation, I am sure was proud of their success. The last Lahar eruption at Mount Saint Helen was in March of 1982. In 1991 Mount Pinatubo erupted and it just started out as an eruption, then the pyroclastic flow started going downward toward the river valley. This turned the eruption into a Lahar. Lastly, over the past 10,000 years there have been over 60 different Lahars at Mount Rainer in Washington. Sure these Lahars have been many sizes and different amounts of energy but they have all been destructive.
Specific details are that Lahar originated from the Javanese language of Indonesia. I get why Lahars are extremely dangerous. It’s because of the speed and energy that is contained, plus it comes out of a volcano which means that it’s hot. Lahars can be enormous. The one at Osceola produced by Mount Rainer created a wall of mud about 140 meters or 460 ft deep. Also, if large enough can produce several flows per second. One last thing Lahars can happen even without volcanic activity.
Lahars are dangerous and if you’re ever close to a river valley located by a volcano you could see a lahar.
In the year 2004 a devastating earthquake occurred right off the coast of Indonesia. With a magnitude of 9.3 it flattened over 225,000 people, and took its record as the second largest earthquake to be seen on a seismograph. The earthquake triggered a series of deadly tsunamis throughout the Indian Ocean. It even shook the earth so much the world moved 1cm.
Any society that lives on an active plate boundary is in danger such as the unexpected slip of the Indo- Australian plate. One of the ways that the people cope with danger is an old folklore of a past encountering. On an Indonesian island, Simeulue, the people remembered the story of a great tsunami that came after a big earthquake in 1907. When they felt the Indian Ocean Earthquake they ran for the hills, saving the entire population.
A second example of how people live with danger is by recognizing the early signs. A 10 year old girl saw receding water and bubbles which she had learned preceded tsunamis. She and her parents cleared the beach and saved many lives. A biology teacher saw the same signs and rescued a busload of vacationers to higher grounds.
A third example is to adapt after a disaster. One way that they did is the united Nations came up with a Indian Ocean Tsunami Warning System. By 2005 they had it all up and running. Some have even suggested forming a new global system that would include the Atlantic Ocean and the Caribbean.
In many parts of the world people live with dangers. In the Indian Ocean the India Plate and the Burma Plate collide a dangerous fault line and a bad place to be. People who live in this area have shown an interesting adaptation towards the danger they face.
It is rememberd as on of the worst natural disasters in the history of the USA.
The magnitude was ranged at 7.7 to 8.1, the Intensity in San Fransico was VIII and in Santa Rosa IX.
The mainshock epicenter occured 2 miles offshore and ruptured on the San Anderas Fault to the north and to the south 296 miles.
Many people were either dead or injured.
The largest surface displacement was 20 feet, and the largest displacement was 28 feet.
Shaking could be felt in Oregon, Los Angeles, and as far as Nevada.
Some of the worst damage happend in San Fansico.
80% of the city was destroyed 90% of the damage was caused by fires.
The fires started due to broken gas lines and arson, the majority was broken gas lines and refugees starting campfires unknowningly about the gas in the air.
Worst of all was the firefighters tried to use dynamite to create fire breaks to stop the fire only destroying more buildings.
Arson was caused by people to get insurnce money because they didnt have earthquake coverage just fire damage and thats basicly insurnce fraud.
Fire destroyed 500 blocks of the city, property damages reached to 235 million dollars the equivelent to 5.1 billion dollars today.
Many people where homeless so the army had to come in and build a reffugee camp, they built 5,610 houses to hold the reffugees.
The camp reached well over the population of 16,000.
In conclusion the world now knows how to sucsessfully deal with earthquakes from the horrors that happend in San Fransico.
TO hour 1
The San Francisco earthquake left 250,000 people out of homes either because their house broke in half from the fault line being right underneath them. The earthquake destroyed 490 blocks and a total of 25,000 buildings. Many buildings were destroyed by the shaking.
The earthquake killed 3,000 people from San Francisco witch was where the epicenter was and there were 189 more deaths elsewhere. Those 189 more deaths were either because they fell down the crack along the 270 miles of fault line.
The government had to pay $350,000,000 to $400,000,000 in repair for getting all the roads fixed from the crack. Also for repairing all 25,000 buildings that got destroyed along the San Andreas fault line.
The earthquake happened at 5:12 A.M. about 20 to 25 seconds later. The after shock came in and lasted for about 45 to 60 seconds. All the people of San Francisco went through a 8.25 earthquake on the Richter Scale.
In conclusion the San Francisco earthquake happened on April 18th at 5:12 A.M. and killed 3,000 people and left more then 250,000 people out of a home and living on the streets. The San Francisco earthquake was a terrible and tragic earthquake for many families that lived in San Francisco.