On what date did the 1980 eruption of Mount St. Helens, in which "Crater Glacier" was formed, occur?
Crater Glacier The Crater Glacier (also known as Tulutson Glacier) is a geologically young glacier that is located on Mount St. Helens, in the U.S. state of Washington. The glacier formed after the 1980 Eruption and due to its location, the body of ice grew rapidly, unknown to the public for nearly 20 years. The glacier once contained ice caves in the smooth ice before the 2004-2008 volcanic activity. The growth of the lava dome and volcanic eruptions from 2004 to 2008 significantly altered the appearance of the glacier. In the same time period, several agencies decided to put an official name on the glacier which, at first, was Tulutson Glacier. A later decision made Crater Glacier the official glacier name. Despite the volcanic activity, the glacier continued to advance and by mid-2008, the glacier completely encircled the lava domes. In addition, new glaciers (rock or ice) have formed around Crater Glacier as well.
Herman LeRoy Fairchild Herman Le Roy Fairchild (April 29, 1850 – November 29, 1943) was an American educator and geologist. He was an early proponent of the theory of meteorite impact causing craters such as that of Meteor Crater, Arizona. Fairchild also left his mark on glacial geology. In that field he is best known for having accurately mapped the proglacial lakes of western New York. He did his field work between the 1888 and the early years of the 20th century. He located strand lines (beaches) and erosional surfaces, determined their altitude, and interpolated between them to show the extent of several large bodies of water. A series of lakes was created as the Wisconsinan glaciation ended and ice sheets retreated during the latest Pleistocene and early Holocene epochs. Fairchild discovered several outlets where each lake drained to the east or west.