New Geophysical Seismic Phenomenon Discovered, Called Stormquakes
You've heard of storms, and you've heard of earthquakes, but have you ever heard of stormquakes? Up until now, that last term hadn't yet been invented.
A Florida State University study coined the new geophysical term upon discovering that massive energetic storms create huge waves in the ocean, which upon hitting ocean banks, create seismic-like reactions.
These are called "stormquakes."
Analysis of 10 years of seismic activity
The team of researchers at Florida State University, led by Dr. Wenyuan Fan, analyzed ten years' worth of seismic activity near ocean banks, or continental shelves.
Dr. Fan described stormquakes as: "This involves [the] coupling of the atmosphere-ocean and solid Earth. During a storm season, hurricanes or nor’easters transfer energy into the ocean as strong ocean waves, and the waves interact with the solid earth producing intense seismic source activity."
During their research, the team discovered over 10,000 stormquakes from 2006 to 2019 off the shores of New England, Florida, and in the Gulf of Mexico, as well as Nova Scotia, Newfoundland, and British Columbia.
"We can have seismic sources in the ocean, just like earthquakes within the crust. The exciting part is seismic sources caused by hurricanes can last from hours to days," Dr. Fan said.
How did the team monitor their findings?
To ensure they were, in fact, researching and locating stormquakes, the team had to have very precise conditions.
Naturally, it had to be a very stormy day, and any potential earthquake had to be ruled out.
The researchers pointed toward the 2009 Hurricane Bill as being a perfect example of a stormquake source.
The hurricane's source was in the eastern Atlantic and grew into a Category 4 hurricane before turning into a tropical storm as it hit the shores of Canada's Newfoundland. It then decreased into a Category 1 hurricane as it approached New England's coast.
As the hurricane hit land, a number of seismic occurrences happened off the shores of Nova Scotia and New England.
Other examples of stormquakes are the 2011 Hurricane Ike, which led to some seismic activity in the Gulf of Mexico, and Hurricane Irene in 2011, which created similar activities off of Little Bahama Bank in Florida.
There is a point to make, though, which is that not all hurricanes lead to stormquakes.
According to the research, stormquakes have seemingly only appeared in very specific locations dotted around North America.
"This suggests that stormquakes are strongly influenced by the local oceanographic features and seafloor topography," said Dr. Fan.
"We weren't even aware of the existence of the natural phenomenon. It really highlights the richness of the seismic wave field and suggests we are reaching a new level of understanding of seismic waves." https://t.co/7vsGUaazHc— MotherNatureNetwork (@MotherNatureNet) October 19, 2019
Stormquakes are an entirely novel discovery, even though they are most likely to have been occurring for many years already. There is still much left to be discovered about them.
The study was published in the journal Geophysical Research Letters.