The Mount St. Helens volcanic eruption is a good case study for A-level students to use in order to improve synopticity within essays.
Here are some key facts and figures that you could include:
- On March 20th, 1980 the volcano began to show signs of potential eruption with moderate earthquakes measuring around 4 the Richter Scale.
- The USGS (United States Geological Survey) started monitoring the volcanic movements with renewed enthusiasm, using seismometers and gas meters.
- On March 29th, a second large crater was discovered, which eventually joined the main crater during the eruption.
- The evacuation of the area was eventually ordered, illustrating the presence of an effective warning system. This was particularly important for forestry workers located on the flanks of volcano.
- However, tourists poured into the area as they didn’t understand the danger.
- A 50 mile exclusion area was introduced around the volcano. However, the eruption was lateral and lahars travelled outside of this exclusion zone. So people located outside of this area thought they were safe but many died due to the unpredicted lateral eruption.
- On May 18th, 1980 (a Sunday morning) Mount St. Helens erupted at 8:32AM.
- A 14 mile high ash cloud was erupted into the air, which darkened the sky.
- During the rescue operations 170 people were rescued (FEMA) and 61 died – a relatively low death rate. This may be because the area surrounding the volcano was scarcely populated.
- Within 1 month of the eruption, the ash plume had travelled around the world.