May 8, 2016
Mount St. Helens Grumbles, Causing Fears Of Another Major Eruption

Mount St. Helens has been grumbling from deep underground, causing scientists to question whether another major eruption is looming.

According to a post on the U.S. Geological Survey Facebook page, more than 130 small tremors have been documented in the Mount St. Helens region in Washington over the past several weeks.

"Beginning March 14, 2016, a number of small magnitude earthquakes have occurred beneath the volcano, at a depth between 2 and 7 km (1.2 to 4 miles). The earthquakes have low magnitudes of 0.5 or less; the largest a magnitude 1.3. Over the last 8 weeks, there have been over 130 earthquakes formally located by the Pacific Northwest Seismic Network and many more earthquakes too small to be located. Earthquake rates have been steadily increasing since March, reaching nearly 40 located earthquakes per week."

The recent quakes around Mount St. Helens are eerily similar to those that preceded the massive eruption on May 18, 1980, which blew off the top of the mountain. Few can forget the images of hot ash spewing across the state and causing deaths, forest fires, and flooding.

While it may seem like a frightening possibility that another massive eruption could occur, volcanologists are not too worried. According to the United States Geological Survey (USGS), the data collected doesn't necessarily point to an imminent eruption.

"There is absolutely no sign that it will erupt anytime soon, but the data we collect tells us that the volcano is still very much alive."

That doesn't mean Mount St. Helens is gearing up for another big one. Prior to the 1980 eruption, more than 10,000 earthquakes led up to the cataclysm. Those began small as well but soon escalated.

According to Livescience, while a 5.1-magnitude quake occurred on the morning of the Mount St. Helens explosion, it was considered moderate with a small chance of damage to buildings.

According to Seth Moran, the scientist in charge of the USGS Cascades Volcano Observatory in Vancouver, Washington, these latest eruptions on Mount St. Helens in no way mirror what happened in 1980.

"What we're looking at [now] is way smaller."

People living near Mount St. Helens should rest assured for the near future. Since the 1980 eruption, Mount St. Helens has been one of the most monitored volcanoes on the planet.

Scientists use a variety of monitoring systems, including seismic monitoring networks, global positioning instruments, and many other devices to pick up even the smallest hiccup produced around the volcano.

And according to all those instruments and monitoring, most of the quakes are undetectable to humans at the surface of the Earth. Most of the quakes occurred miles below the surface and had magnitudes of 0.5 or less, with the largest reaching only magnitude 1.3.

Another reassuring sign that Mount St. Helens may remain relatively quiet is a lack of any quakes close to the surface and there has been no indication of ground inflammation, which is a sign of an underground buildup of gas.

Experts say all indications point to a simple "magma recharging process." This occurs when magma refills areas underneath the volcano. The weight of the magma moves the ground a bit, causing small earthquakes.

These same patterns have occurred at various times since the 1980 eruption of Mount St. Helens. These swarms of quakes also appeared in the 1990s, 2013, and 2014, some of which had much higher magnitudes.

Because Mount St. Helens remains an active volcano, an eruption will occur at some point. However, scientists are offering reassuring announcements that there is no sign of an impending catastrophe.

"As was observed at Mount St. Helens between 1987-2004, recharge can continue for many years beneath a volcano without an eruption."

There have been quite a few quakes of late, however, and one just never knows. Mount St. Helens just might have the final say in this.

[Photo by Scott Taylor.U.S. Navy via Getty Images]