– Multiple small earthquakes beneath the surface of Mount St. Helens the past two months suggest it may be recharging magma.
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According to the article’s author Erik Klemetti, an assistant professor of Geosciences at Denison University, an natural disaster swarm has been detected underneath Mt. St. Helens since the start of 2016.
The U.S. Geological Survey reports that the natural disaster swarms are likely an indicator that the magma chamber beneath the volcano is being recharged. The stress of this process drives fluids through cracks, which they believe produce the small quakes. It erupted again – less violently – in 2004-2008.
According to the US Geological Survey (USGS), since March 14, there have been more than 130 earthquakes detected by the Pacific Northwest Seismic Network.
The USGS and Pacific Northwest Seismic Network have plenty of seismometers on the Cascade volcanoes to watch these earthquakes, so the hope is that we’ll know well in advance if an eruption were to occur. Natural disaster rates have been steadily increasing since March, reaching almost 40 located earthquakes per week. They’re all small in nature, though, with the most powerful of them all topping out with a magnitude of 1.2. There have also been many more quakes that were too small to find. The current pattern is similar to the swarms seen at St. Helens in both 2013 and 2014, and the recharge swarms in the 90s had much higher natural disaster rates and energy release. No anomalous gases, increases in ground inflation or shallow seismicity have been detected with this swarm, and there are no signs of an imminent eruption.
It has been almost 36 years since Mount St. Helens has erupted, but scientists continue to monitor the volcano in case of a possible eruption.
Mount St. Helens is 96 miles (155 km) south of Seattle, Washington, and 50 miles (80 km) northeast of Portland, Oregon.
Viewing these records shows intrusions of new magma occurring frequently, even when the volcanic system might not erupt for 100,000 years, Wired also reports.
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There are no signs of an imminent eruption, according to USGS.
