Earthquake! – January 29, 2020
Yesterday, January 28, 2020, a 7.7 magnitude earthquake hit between Jamaica and Cuba. It was so powerful that shaking was felt nearly 500 miles away, in Miami, Florida! The epicenter was at a shallow 6 miles below the surface, prompting tsunami fears as shallower earthquakes tend to be more destructive. Thankfully, there were no reports of casualties or serious damage.
So, why do some earthquakes in the ocean cause tsunamis and others don’t? Earthquakes trigger tsunamis when seismic activity causes land along fault lines to move up or down. When parts of the seafloor shift vertically, either raising or lowering, entire water columns can become displaced, creating a “wave” of energy. Earthquakes that push land mainly in the horizontal direction are less likely to cause devastating waves, because the land does not raise or lower the water above it enough to cause a tsunami. According to the US Geological Survey, this earthquake was a “strike-slip” type, where the North American and Caribbean tectonic plates scraped past each other. Thus, there was more horizontal than vertical motion and lesser tsunami risk.
But when tsunamis do hit? The wave can travel at up to 500 or 600 miles an hour – roughly the speed of a jet!
If you were in the vicinity and felt the earthquake, contribute to citizen science here: https://earthquake.usgs.gov/ear…/eventpage/us60007idc/tellus
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