Is Mt St Helens about to blow? America's most dangerous volcano is recharging - 43 years after catastrophic eruption that was the worst in US history

Mount St. Helens has begun rumbling again recently - more than four decades after the worst eruption in US history.

Since February 1, 2024, approximately 350 earthquakes have been recorded at the 8,300-foot Washington state volcano by the Pacific Northwest Seismic Network. 

Most of these - more than 95 percent - have been less than magnitude 1.0 and are too small to be felt at the surface. 

The largest quake recently felt at the volcano, which is located in southwestern Washington about 50 miles northeast of Portland, Oregon, was a magnitude 2.0 on May 31, 2024. 

There are fears the earthquakes could lead to another massive explosion reminiscent of 1980s eruption that left 57 people dead and permanently altered the area's ecosystem. 

Mount St. Helens has begun rumbling again recently - more than four decades after the worst eruption in US history. (Pictured: the 1980 eruption)

PITCURED: The aftermath of the 1980 eruption 

In early June, the number of earthquakes recorded per week reached a peak of 38 events per week, mostly happening around 4.6 miles below the crater floor. 

Specialized equipment has detected that magma has been flowing through chambers deep underground, causing the volcano to recharge. 

It comes after a surge in quakes was also recorded in 2023.

The 1980 eruption left 57 people dead

'Short-term increases in earthquake rates are common at Mount St. Helens and are considered part of background seismicity,' experts at the Cascades Volcano Observatory said in a statement this week. 

'The last two periods of elevated seismicity (in 2023 and 2024) represent the largest short-term increase in earthquake rates since the last eruption ended in 2008.'

However, similar sequences involving even more quakes broke out in 1988 to 1992, 1995 to 1996, and 1997 to 1999. None of these directly triggered an eruption. 

The quakes are thought to be caused by pressurization of the magma transport system, which in turn is triggered by the arrival of additional magma, a process called recharge. 

Since February 1, 2024, approximately 350 earthquakes have been recorded at the 8,300-foot Washington state volcano by the Pacific Northwest Seismic Network

Magma gradually bubbles through the lower crust and builds up in a reservoir around 2.5 to six miles below sea level. 'Recharge' events break out when magma enters this reservoir, causing quakes. 

'There have been no significant changes in other monitoring parameters (ground deformation, volcanic gas or thermal emissions) and no change in hazards at Mount St. Helens as a result of this activity,' the Observatory concluded.   

However, in 1980, small earthquakes were recorded at the site just before the deadly eruption. 

On May 18, 1980, residents flooded the area as they sat in open fields and rooftops as rumors of a volcanic eruption spread. Millions all over the world waited around for two months to see what would happen next. 

But on that morning, at 8.32am, the results turned out to be deadly as a magnitude-5 earthquake struck, causing the volcano to lose its crypto-dome and erupt. 

Those in the area had nowhere to take cover. 

The volcano fatally exploded (pictured) on May 18, 1980 and took the lives of 57 people. Just two days before small earthquakes were recorded at the site

More than 400 earthquakes have been detected beneath the surface of the volcano in recent months. There have been more than 2,000 earthquakes recorded at the site since 2010

The volcano exploded sideways and sent an enormous landslide of a super-heated mix of ash, rock fragments and gas flowing downslope. The ash and gas then rose and blocked the sun, turning the sky completely dark. 

Venus Dergan told Portland Monthly she and her boyfriend, Roald Reitan, were camping on the south fork of the Toutle River, just 30 miles from the volcano. 

They woke up to a blaring alarm from the nearby town of Toutle and said they didn't hear the eruption but saw water rush toward them. 

At the time of the 1980 eruption only one monitoring system (pictured) was in place, but currently there are 20 systems

'We were lucky that we got out of the tent when we did. They probably would have never found us.

'We would've been buried alive,' Dergan said.  

Destructive mudflows, also known as lahars, swept up homes and trucks as officials closed bridges and stalled railroad track operations. 

Most of the debris from the seismic event turned westward, down the North Fork Toutle River and formed a mound of deposit. 

The total avalanche volume equaled a measurement of 1million Olympic-sized swimming pools.

Trees were also blown to the ground or scorched by the brutally hot lava, leaving the once-dense forest virtually empty. 

Loads of volcanic ash and blistering hot lava erupted from the summit and caused health issues for those in the area at the time 

Destructive mudflows, also known as lahars, swept up homes and trucks as officials closed bridges and stalled railroad track operations 

The volcanic ash fell like snow throughout Washington, Idaho and western Montana. Officials had to close highways for weeks and airlines canceled more than 1,000 flights. 

In the days following the devastation, an estimated 540million tons of ash drifted up from the structure and settled over a total of seven states. 

The aftermath also drew researchers from around the world as they began to study the impacts of the ash, and navigated ways to clean up the farmlands, roads and water treatment facilities. 

The ash itself left a lasting impact on human, animal and plant life. When volcanic ash is dispersed it can cause respiratory and eye issues, along with skin irritation. 

Toxic gases like carbon dioxide and fluorine commonly found in ash directly affected crops, animals and caused human illness. 

The disastrous eruption also caused large amounts of mud, water and debris to intrude on banks and flooded low-lying valleys. Rock sediment clogged channels in the Toutle, Cowlitz and Columbia Rivers. 

To this day, those rivers continue to transport this sediment downstream ten times greater than before the 1980 eruption, the United States Geological Survey reported. 

The natural disaster killed thousands of animals and caused over $1billion in damage.

One of the people killed that day was Robert Landsburg, a 48-year-old photographer who was just a few miles from the summit. 

The Seattle-born man dedicated himself to his craft up until the very moment he died, as he knew there was no way out of the catastrophic event. 

Instead of trying to escape, he continued to take photographs and made sure that he protected his camera and film from the blistering hot lava and ash that consumed him. 

The photographs captured in his final moments were published in the January 1981 issue of National Geographic and are still admired to this day.   

Another volcano eruption at Mount St. Helens took place from 2004 to 2008 and allowed scientists to investigate just how it works. It also allowed them to advance their monitoring systems that detect when the next explosion might take place. 

At the time of the 1980 eruption only one monitoring system was in place, but currently there are 20 systems.