Strong earthquakes continue to rock the Caribbean after yesterday’s powerful 7.7 quake located between Jamaica and Cuba. More quakes continue to rock Puerto Rico’s south coast while a new swarm area of earthquakes north and west of Puerto Rico just started too.
Yesterday’s very strong and potent 7.7 magnitude earthquake was strong enough to trigger a tsunami alert within 300 kilometers ( 186 miles) of the epicenter epicenter. Fortunately, because the earthquake movement was more side to side than up and down, the threat of tsunami was reduced and only a small tsunami was detected in the western Caribbean.
While it didn’t create a major tsunami, it has set the stage for a spree of aftershocks, most of which are occuring to the west of yesterday’s epicenter near the eastern side of the Cayman islands. Today alone there have been at least 6 magnitude 4.1 or greater quakes here, including a 5.1 that struck 114km north-northwest of Lucea, Jamaica a short time ago.
The southern coast of Puerto Rico, hit hard by an earthquake just weeks ago, continues to rock and roll. A 3.1 quake struck near Guanica, Puerto Rico earlier today, a short distance from where the potent 6.4 quake hit on January 7, destroying many buildings and killing one person. A swarm has impacted this portion of Puerto Rico since December 28, with numerous daily quakes impacting the area. In the last 30 days, the area has seen 2,372 earthquakes with a magnitude of 1.5 or greater; 288 struck in the last 7 days, and 11 in the last 24 hours. Today’s strongest hit San Antonio in Aguadilla, Puerto Rico; that was a 4.6 at about 11am local time today.
While geologists and seismologists have been monitoring the activity on Puerto Rico’s south coast and now near Jamaica and the Cayman Islands, eyes are also turning north of Puerto Rico where a new swarm appears to be unfolding. In the last 24 hours, 6 moderate quakes struck an area northwest of Puerto Rico and east of Punta Cana, Dominican Republic. The latest, a 4.6 struck this morning. It is not yet known if those quakes are foreshocks to something larger looming.
Seismologists don’t believe there is a link between the Jamaica quakes and the Puerto Rico ones. Each area appears to be having earthquakes separate from the other. Dr. Lucy Jones took to Twitter yesterday to explain the difference. Dr. Jones is aa Research Associate at the Seismological Laboratory of Caltech, a post she has held since 1984. “The Jamaican M7.7 is not related to the Puerto Rican quake. Triggering of another quake happens within ~3x length of the first fault,” she Tweeted. The Puerto Rico quake was on a “~15 mile long fault, but the M7.7 was over 800 miles away, ” she added. “Way too far away to be related.”
While the quakes aren’t directly linked, it isn’t unexpected to find earthquake, tsunami, and even volcanic activity here. All these quakes have been located near the edge of the Caribbean Tectonic Plate, which sits under Central America, the Caribbean Sea, and the north coast of South America. Roughly 1.2 million square miles in area, the plate is moving along the North American Plate; that collision area is very close to where all of this week’s quakes have occured.
In fact, many strong earthquakes and destructive tsunamis have occured in the past in this region. In August of 1946, a 8.1 quake struck the Dominican Republic. It generated a destructive tsunami; more than 2,500 people were killed in that natural disaster. A destructive tsunami was also formed by a 7.1 earthquake in Puerto in October of 1918; that disaster claimed more than 100 lives. A tsunami also formed after the January 1907 6.5 earthquake in Jamaica; that event was responsible for 1,000 deaths there. The deadliest quake hit the region in February of 1843. Then, in the Lesser Antilles, a 8.3 quake struck, killing an estimated 4,000-6,000 lives. Historical records also show that Jamaica had a powerful quake in 1692 which claimed around 5,000 lives there too.
Volcanoes also dot the Caribbean, with well-known ones around St. Kitts, Dominica, St. Lucia, St. Estatius, and Saba. The most popular eruption in the area in recent times was on Monsterrat. In July of 1995, the previously dormant Soufriere Hills volcano roared to life; that eruption destroyed the island’s capital city of Plymouth. Between 1995 and 2000, two-thirds of the island’s population was forced to flee, leaving fewer than 1,200 people on the island by 1997. Even Jamaica has a volcano; it produced the Low Layton Lava, which forms a prominent east-west ridge on the north shore of the island.
