The diagram below shows that the three largest Yellowstone eruptions emitted much more material than the eruptions of Mount St. Helens (1980), Mount Pinatubo (1991), Krakatau (1883), Mount Mazama (7,600 years ago), and Tambora (1815).
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through...
The May 18, 1980 eruptive column at Mount St. Helens fluctuated in height through the day, but the eruption subsided by late afternoon. By early May 19, the eruption had stopped. By that time the ash cloud had spread to the central United States. Two...
The science of forecasting a volcanic eruption has significantly advanced over the past 25 years. Most scientists think that the buildup preceding a catastrophic eruption would be detectable for weeks and perhaps months to years. Precursors to volcanic...
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been...
Before May 18, 1980, Mount St. Helens' summit altitude of 9,677 feet made it only the fifth highest peak in Washington State. It stood out handsomely, however, from surrounding hills because it rose thousands of feet above them and had a perennial cover...
Yellowstone is a plateau high in the Rocky Mountains, and is snowbound for over six months per year. The mean annual temperature is 2.2°C, barely above the freezing point of water. However, Yellowstone is also an active geothermal area with hot springs...
Ground deformation (swelling, subsidence, or cracking) is measured with a variety of techniques, including Electronic Distance Meters (EDM), the Global Positioning System (GPS), precise leveling surveys, strainmeters, and tiltmeters. EDMs use lasers to...
Earth's heat is released in Yellowstone by two main processes, conduction and convection: 1. Conduction is the movement of heat from hotter material to colder material. A common example of conduction is when heat from a stove is transferred through the...
The magma chamber is believed to be about 40 by 80 kilometers across, similar in size to the overlying Yellowstone caldera. The top of the chamber is about 8 km deep and the bottom is around 16 km deep. However, the chamber is not completely filled with...