Volcanoes in Alaska, Washington state, Oregon and Hawaii have recently been rumbling and even spewing lava, enough to spark a swarm of news stories. But despite the jolts and temblors, geologists say there’s no cause for alarm.
“Volcanoes can be unpredictable and there’s always chance that something bad will happen, but these recent seismic events along the Pacific Ring of Fire from Alaska to Washington to offshore Oregon are probably not directly related to each other,” said Natalia Ruppert, a seismologist with the U.S. Geological Survey’s Earthquake Science Center in Seattle.
“This is what volcanoes do,” she said. “They come to life for a while, sometimes the earthquake activity leads to an eruption and sometimes it doesn’t.”
Most of the U.S. volcanoes that have been making themselves known since spring woke up a bit, shook themselves off and then fell back into slumber.
Two, one in Hawaii and one in Alaska, are in the midst of active and ongoing – but relatively small and non-threatening – eruptions.
While it all might seem ominous, it isn’t. It’s simply part of life on a dynamic, seismically active planet.
There’s no direct connection between any of these, said Ruppert. “The distance between these (seismic) activity centers is thousands of miles.”
While volcanoes have always been a part of the West Coast’s geography, it might seem that this is an especially busy time for these mountains caused by fissures in the Earth’s crust that go down to the mantle below.
But seismologists and volcanologists are keeping a careful eye on them, said Ruppert. “This is why the federal government funds earthquake and volcano monitoring efforts through the Department of the Interior and USGS.”
Consider these recent events:
The volcanoes are located along what’s known as the Ring of Fire, a 25,000-mile long, horseshoe-shaped string of volcanoes and seismically active areas that stretches from the southern tip of South America, up along the West coast of the United States, across the coast of Alaska, down through Japan all the way to New Zealand.
It’s created by the Pacific plate sinking below the North American plate and is the most seismically and volcanically active zone in the world, according to the U.S. Geological Survey.
Far to the west in Hawaii, Mt. Kilauea continues to erupt, though as of July 11 it has not been exhibiting the massive fountains of lava that had been taking place earlier in the month. On July 9, USGS said the most recent eruption had ended.
Hawaii’s volcanoes are not part of the Ring of Fire. The island chain was (and is still being) formed by a volcanic hot spot that has so far created 15 different volcanoes that stretch 3,800 miles across the Pacific.
In Hawaii’s case, the volcanoes are the result of a heat source deep within the Earth’s mantle. The plume of magma coming from that hot spot in the ocean floor remains stationary as the Pacific Plate slowly – 2 to 4 inches a year – moves over top of it.
This is why Hawaii’s oldest volcanoes, on Kauai, are 5.5 million years old while the newest, on the Big Island, are only 700,000 years old and still growing.