Evidently, Hurricane Irma is so strong that it’s being detected by equipment made to measure earthquakes.

Stephen Hicks, a seismologist in the United Kingdom stated to 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.”

Hicks explained that the noise is a result of high winds, swaying trees, and crashing waves.

Is this unusual? Not really, says Hicks. Large storms like this often register on seismographs. “We saw this for Hurricane Harvey on seismometers located close to Houston.”

Featured image: NOAA Satellite