Mount St. Helens shakes 120 times within a week as volcano recharges
In less than a week, four swarms of more than 120 earthquakes shook Mount St. Helens in late November. Although they were too small to be felt even by someone standing directly over their epicenters, scientists say they reveal the volcano is likely recharging. Read more
Researchers find evidence for a cold, serpentinized mantle wedge beneath Mt. St. Helens
Despite the previous research, the structure of the deep magmatic plumbing system beneath Mount St. Helens and its context within the broader Cascadia subduction system remain poorly resolved despite the genetic link between subduction and arc volcanism. Recently, researchers including postdoctoral researcher Steven Hansen, along with mentor and Assistant Professor Brandon Schmandt at The University of New Mexico, have been searching for additional answers surrounding the magmatic system of Mount St. Helens as part of a multi-year collaborative research project involving several institutions. Read more
A 3-D model of a volcanic explosion, based on the 1980 eruption of Mount St. Helens in Washington state, may enhance our understanding of how some volcanic explosions occur and help identify blast zones for potentially dangerous locations, according to an international team of volcanologists. The researchers created the 3-D model using the parameters of the Mount St. Helens blast including equations to determine mass, momentum and the heat energy of the gas, along with the size, density, specific heat and thermal conductivity of the solid particles. Read more
An earthquake at 8:32:17 a.m. PDT (UTC7) on Sunday, May 18, 1980, caused the entire weakened north face to slide away, suddenly exposing the partly molten, gas- and steam-rich rock in the volcano to lower pressure. Read more
Title: Multiphase-flow numerical modelling of the 18 May 1980 lateral blast at Mount St. Helens, USA Authors: T. Esposti Ongaro, C. Widiwijayanti, A.B. Clarke, B. Voight and A. Neri
Volcanic lateral blasts are among the most spectacular and devastating of natural phenomena, but their dynamics are still poorly understood. Here we investigate the best documented and most controversial blast at Mount St. Helens (Washington State, United States), on 18 May 1980. By means of three-dimensional multiphase numerical simulations we demonstrate that the blast front propagation, final runout, and damage can be explained by the emplacement of an unsteady, stratified pyroclastic density current, controlled by gravity and terrain morphology. Such an interpretation is quantitatively supported by large-scale observations at Mount St. Helens and will influence the definition and predictive mapping of hazards on blast-dangerous volcanoes worldwide.
Johnston Ridge Observatory at Mount St. Helens National Volcanic Monument will reopen for the season May 15, with several new exhibits and a new outdoor amphitheatre. Read more
USGS has released high resolution lidar images for the Mount St Helens cone area. You can get a 17×22 inch pdf that can be printed as a study sheet or a 32×42 inch pdf that can be plotted for use as a poster.