On May 18, 1980, Mount St. Helens in Washington State experienced a huge volcanic eruption after a magnitude 5.1 earthquake. During the eruption, hot ash and pumice poured down the west, south, and east sides of the mountain, melting the snow and ice at the top of the volcano and producing volcanic mudflows. Which type of process first occurred in the ecosystem around Mount St. Helens after it erupted?

primary succession

Explanation:

Primary succession starts in regions where there is no soil or where the soil is incapable of sustaining life due to any recent lava flows or newly formed sand dunes. Primary succession may lead to the formation of islands on land formed from glacial retreats or on new volcanic rock.

Primary succession occurred in the ecosystem around Mount St. Helens after the volcano erupted.