The Earth Is Shaking Under Irma as the Hurricane Powers Through the Caribbean
The monstrosity of Hurricane Irma is shaking the earth in the Caribbean Islands.
The winds from the hurricane are so strong that seismometers—instruments used to measure earthquakes—are detecting movement in the ground, a seismologist at the University of Southampton in the United Kingdom, Stephen Hicks, told USA Today.
“What we’re seeing in the seismogram are low-pitched hums that gradually become stronger as the hurricane gets closer to the seismometer on the island of Guadeloupe,” said Hicks.
As Irma approached the island of St. Maarten in the northern Caribbean, there was a dramatic increase in seismic activity, and then the seismometer went offline for some unknown reason.
Hicks explains it is the intense winds from the hurricane, reaching 185 mph in some areas, that are generating reverberations in the ground. The increase in seismic energy is mostly created by the increase in wave activity in the ocean, which is similar to what the U.K. experiences when they get winter storms, Hicks tweeted. But this can make it difficult to distinguish between movement from storms and small earthquakes.
Hicks says that this type of vibration in the earth is different to that caused by earthquakes, which “occur tens of (miles) deep inside Earth’s crust.”
But a seismometer can detect such vibrations, no matter their origin. Seismometers can also be used to detect nuclear explosions.
It is not uncommon for seismometers to detect energy from large storms like Irma.
“We saw this for Hurricane Harvey on seismometers located close to Houston,” Hicks told USA today.
Scientists also recorded flexing of the Earth’s crust as a result of the flooding after Hurricane Harvey made landfall almost two weeks ago. GPS data showed that the Houston area was pushed more than half an inch lower by the sheer weight of Harvey floodwaters.
At least 60 people died in the aftermath of Hurricane Harvey, with the cost of damages expected to reach as high as $180 billion.
Irma is expected to pass just 30 miles north of San Juan, Puerto Rico between 6 p.m. and 8 p.m. on Wednesday before scraping the north coast of the Dominican Republic on Thursday. The hurricane will reach Cuba and the Bahamas later in the week before most likely reaching parts of Florida this weekend. Precise trajectories for Irma’s path remain uncertain.
Irma has just broken the all-time record for highest sustained wind speed as the strongest Atlantic storm on record.
Both Florida and Puerto Rico have declared states of emergency in preparation for the storm’s arrival. Additionally, many counties in South Florida will soon begin the process of mandatory evacuations.
“Normally, people here don’t like to prepare,” Gary Palmer, a 60-year-old deputy sheriff who visited a home supply store in Fort Lauderdale, Florida, told Reuters. “But what happened in Texas opened up everybody’s eyes.”
For updates on Hurricane Irma and tropical storms Jose and Katia, visit www.nhc.noaa.gov.