Lahars are deadly volcanic mudflows commonly found at Mt. Rainier. A deadly lahar occurred in Nevado del Ruiz in Colombia.
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.