Scientists have detected a “large swarm” of earthquakes off the coast of Washington, recording up to 200 in a single hour over one day.
Geologists at the University of Washington said the earthquakes could cause the Juan de Ruca ridge to erupt within a few weeks or years, but the effects are thought to be mild and probably not affect anyone on land.
The underwater volcano lies more than 16,000 feet below the Pacific Ocean and about 150 miles off the coast of Washington.
With more than a thousand small earthquakes detected in one day, this is the highest activity detected at the site since 2005, and researchers said the volcano could soon erupt.
This photograph shows the seafloor on the Endeavor segment of the Juan de Fuca Ridge, the location of the recent “swarm” of earthquakes.
The team said data collected when the volcano erupts could reveal how the Earth’s crust was formed over time by cooled magma, but noted that could happen in a few weeks or a few years.
On March 6, the group’s real-time monitoring network detected the earthquakes, which registered a magnitude of 4.1, relatively mild compared to famous damaging earthquakes like the 1906 San Francisco earthquake, which registered a magnitude of 7. 9.
That earthquake and the fires that devastated the cities caused the death of about 3,000 people.
The “great swarm” of earthquakes followed several days of increasingly frequent earthquakes, according to Canada Ocean Networks (ONC), which collects data for researchers to study.
The spike indicated a possible “imminent magmatic rupture,” the research group reported.
A magmatic rift, which occurs when the Earth’s crust breaks open for some reason and spills out molten rock, is a natural phenomenon that can form a new ocean floor, according to Zoe Krauss, a doctoral candidate in marine seismology at the University of Washington.
In the case of the Juan de Fuca Range, this rupture will be the result of two plates separating from each other, opening a giant crack for magma to flow at about 1,500 degrees Fahrenheit.
ONC officials have emphasized that the effects will be mild and local, and that the earthquake is very unlikely to be felt by residents on land.
It is also unlikely to trigger tsunami activity, since a tsunami is caused by a different type of movement at tectonic plate boundaries: pushing and sliding, rather than separating.
‘No one should be alarmed by this large swarm of earthquakes. They are very far from the coast and do not cause any danger. Rather, the data are interesting to the scientific community and certainly not threatening,” Kate Moran, ONC president and CEO, said in the ONC statement.
The impending volcanic eruption has scientists excited because it will offer a real-time view of how the Earth formed.
As lava spills out of a crack in the Earth’s crust, it will heat the water around it and the ocean will likely even bubble like soda.
Geologists at the University of Washington observed the earthquakes this month near the Endeavor segment of the Juan de Ruca Range, which lies more than 16,000 feet below the Pacific Ocean and about 150 miles off the coast of Washington.
This spectrogram shows all the earthquakes generated in just a few minutes on March 6. It was generated from audio recording data that captures seismic activity.
When the lava hardens, a new layer of seafloor will appear, a sample of what it was like when our planet first formed its crust.
Scientists have been studying the site for almost 30 years.
Investigation of the unique seafloor vents located on the Juan de Fuca Ridge offers unique opportunities to study how the Earth’s crustal war was first created, as well as the strange marine life that exists around the site.
But this will be the first time they will be able to observe a volcanic eruption with sound recording equipment and temperature probes.
This Fetch device monitors seismic activity on the seafloor as part of ONC’s NEPTUNE observatory. A pair of deep-sea lobsters investigate
These tools will add to seismographs that have been installed since the last underwater eruption at the site that occurred between 1999 and 2005.
OCN researchers have observed an increase in seismic activity at the monitoring site near the Endeavor segment.
“It’s about 10 times more active than normal,” said Jesse Hutchinson, a junior scientist at ONC, based at the University of Victoria.
Hutchinson and his colleagues had detected more than 2,000 earthquakes in a single day, he said. he told CBC.
Researchers expect this event to recur approximately every 20 years, OCN officials said.
ONC operates its vast NEPTUNE monitoring network that tracks activity throughout the area, including the tilt of the seafloor, seismic activity and the chemical composition coming from the ‘black smokers’ vents that spew black clouds of hydrogen sulfide, food for living chemosynthetic worms. near the vents.
Through this underwater observatory, scientists can predict when a volcanic eruption is coming.
‘We can use seismic activity to track the level of stress built up in the Endeavor segment in real time using seismic data provided by Ocean Networks Canada. “More earthquakes mean more stress buildup,” Krauss said. “The NEPTUNE observatory data set has allowed us to observe significant increases in the rate of earthquakes in recent years.”
And the instruments not only allow scientists to track changes over time, but also in near real time during an event like a volcanic eruption.
During the last eruption the only tools available were seismometers to detect tremors.
“Having a full set of instrumentation instead of just seismometers allows us to immediately see what else was happening, such as temperature changes inside a black smoker, or instruments starting to tilt, or listening through hydrophones if there were any hisses or drops. “If that were to happen, it would break up the seafloor,” said Martin Scherwath, senior scientist at the ONC.
Unfortunately for marine life around the eruption site, magma ruptures can cover existing habitats.
HOW EARTHQUAKES CREATE TSUNAMIS
Most earthquakes occur along the edges of tectonic plates, known as plate boundaries.
When two blocks of Earth meet at the boundary of a converging plate, the two plates collide with each other. In this case, one may slide up due to the pressure.
If an earthquake pushes the seafloor up, it could push the water covering it into surrounding areas.
Even if the sea floor were to rise just a few meters, this could be enough to displace several cubic kilometers of water and send a series of waves from the earthquake’s epicenter.
Tsunami waves move away from the earthquake epicenter in all directions.
The height of tsunami waves on the coast depends on several factors, such as the distance and direction from the epicenter of the earthquake, the depth and shape of the sea floor, and the shape of the coastline.