The ash plumes, red alerts and evacuations caused by the Kilauea volcano’s eruption are stirring up wonder and worry in Hawaii, but they’re also stirring up memories on the 38th anniversary of Mount St. Helens’ big blast in Washington state.
St. Helens’ eruption of May 18, 1980, ranks as the deadliest volcanic event in U.S. history. Fifty-seven people were killed, and hundreds of square miles of forest were destroyed. Ash rose 16 miles into the sky and was carried by the wind as far east as Montana.
I was one of the journalists who got caught up in the eruption’s aftermath, as an assistant city editor for The Spokesman-Review in Spokane, Wash. Even hundreds of miles away, the cloud of ash turned the afternoon to night. A thin layer of pumice coated the entire city, gumming up traffic and forcing a lot of us to don face masks when we stepped outside.
Mount St. Helens staged a seismic sequel of sorts that simmered from 2004 to 2008. Swarms of small earthquakes still occasionally sweep over the volcano’s flanks.
#OnThisDay in 1980, M5.1 #EQ shakes Mount St. Helens. The northern flank of the volcano slides away in massive landslide (largest in recorded history), followed by a lateral blast traveling 300 mph. Forest within 6+ miles of the blast is leveled https://t.co/Yr8Iwln3pc pic.twitter.com/jRmSHec4W2
— USGS (@USGS) May 18, 2018
Is Kilauea a case of deja vu all over again? Seismologists say the Hawaiian eruption represents a different breed of volcanic activity. “Kilauea and Mount St. Helens are different in almost every imaginable way,” University of Buffalo geologist Tracy Gregg told USA Today.
Kilauea is a flat, shield volcano, while St. Helens was an imposing stratovolcano that had an impressive cone before its top 1,300 feet blew off. The lava that exudes from Kilauea tends to ooze slowly and smoothly, like honey. In contrast, St. Helens’ lava was thicker, stickier and more explosive, largely because of the gas trapped inside the molten rock.
The domino effects set off by the St. Helens eruption — including melting ice and snow, mudslides, debris flows and flooding — added dramatically to the devastation in 1980.
There’s plenty of devastation in Hawaii as well, ranging from the road-destroying lava flows to the refrigerator-sized boulders thrown out by Kilauea. But thanks in part to the scientific lessons learned from St. Helens and other past eruptions, seismologists and emergency officials are better able to anticipate the hazards.
To mark the St. Helens anniversary, check out my remembrance of things past — and take a look through these images documenting Kilauea’s awe-inducing eruption:
May is Volcano Preparedness Month in Washington state, and to help the cause, the U.S. Geological Survey has put together a webpage with links to resources and information sources. When it comes to Kilauea, the USGS Volcanoes Facebook page and Twitter account are good places to find updates.