Lava, ash flows, mudslides and nasty gases: Good reasons to respect volcanoes
Posted by admin on 8th May 2018

Volcanoes are beautiful and awe-inspiring, but the ongoing eruption of Kilauea on Hawaii’s Big Island is showing how dangerous these events can be. So far this event has destroyed dozens of homes and displaced hundreds of people, but no deaths or serious injuries have been reported. Other volcanic eruptions have had deadlier impacts.

As a volcano scientist, I’m very aware of deadly volcanic eruptions can be, even the “nonexplosive” kind we’re seeing in Hawaii now. Since A.D. 1500, volcanic eruptions have killed more than 278,000 people.

Today there are 1,508 active volcanoes around the world. Each year, some 50 to 60 of them erupt. Around 800 million people live within volcanic risk zones. Volcanologists study and monitor volcanoes so that we can try to forecast future eruptions and predict how widely the damage could reach.

When mountains explode

Volcanic eruptions can be broadly divided into two types: explosive and nonexplosive. Explosive eruptions occur when magma, which is molten rock in the ground, contains gas. These eruptions are so energetic that the magma is pulverized into small rock particles, called volcanic ash.

Explosive eruptions are responsible for the highest number of volcanic-related deaths. These events can distribute volcanic ash hundreds of miles from the volcano, causing billions of dollars in air travel disruption, water supply pollution and damage to power lines, structures and machinery. Krakatoa in the Pacific (1883) and Mount St. Helens in Washington state (1980) are examples of explosive eruptions.