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Before the eruption of May 18, 1980. |
After the eruption of May 18, 1980. |
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Forming of the bulge. |
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Earthquake triggers North face of slope to slide. |
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Debris avalanche and lateral blast. |
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Vertical eruption. |
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May 18, 1980 - 8:27:00 5 Minutes before a 5.1 magnitude earthquake beneath the mountain. |
May 18, 1980 - 8:32:47 The north flank collapses, beginning of the debris avalanche. |
May 18, 1980 - 8:32:49 Lateral blast and vertical eruption starts. |
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May 18, 1980 - 8:32:53 The rock slide has now advanced to a level, which causes the cryptodome to become fully exposed. |
May 18, 1980 - 8:33:03 Lateral blast overtakes the debris avalanche. |
May 18, 1980 - 8:33:18 Vertical eruption blasts away blocks, which slided from the crater into the vent. |
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Impact on the environment by the pyroclastic flow, mudflow, lateral blast and debris avalanche. |
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Mount St. Helens as on May 17, 1980 |
Eruption plume |
Mount St. Helens as on May 19, 1982 |