Puerto Rico Trench

The Puerto Rico Trench is a very deep part of the ocean located between the Atlantic Ocean and the Caribbean Sea. It lies just north of the island of Puerto Rico and is the deepest spot in the whole Atlantic Ocean. This trench forms where several large pieces of Earth’s surface, called tectonic plates, meet and move against each other.

The area around the Puerto Rico Trench is where the Lesser Antilles begin and where the South American plate meets the Caribbean plate. It is also close to where the North American plate moves alongside the Caribbean plate. These moving plates create faults and trenches, shaping the ocean floor.

Scientists have studied this area and found that earthquakes happening near the trench could cause big waves called tsunamis. In the past, such as during the 1918 San Fermín earthquake, Puerto Rico experienced a harmful tsunami that caused damage. Understanding the Puerto Rico Trench helps scientists predict and prepare for such natural events in the future.

Description

The Puerto Rico Trench is the deepest part of the Atlantic Ocean. It stretches for 810 kilometres (503 miles) and reaches depths between 8,376 metres (27,480 feet) and 8,740 metres (28,675 feet). The deepest spot is often called the Milwaukee Deep. In 2018, a special underwater vehicle named DSSV Pressure Drop helped find this spot using special sound waves, and later, another vehicle called DSV Limiting Factor went down to check the depth.

Geology

The trench is found where two large pieces of Earth’s crust, called plates, move past each other. The Caribbean plate moves eastward compared to the North American plate. At the trench, the North American plate moves slowly beneath the Caribbean plate. To the southeast, the South American plate moves beneath the Caribbean plate in a different area called the Lesser Antilles subduction zone, which causes volcanoes in that part of the Caribbean Sea.

Although some nearby islands like the Virgin Islands, Puerto Rico, Hispaniola, Cuba, and Jamaica were once part of a volcanic area, they no longer have active volcanoes. These islands can still face strong earthquakes and tsunamis. The Puerto Rico Trench has caused very powerful earthquakes in the past and could do so again. Scientists have also found that a special mass under the trench affects gravity and can make navigation tools less accurate.

Public awareness

Many people living near the Puerto Rico Trench do not know about the risks of earthquakes and tsunamis. Since 1988, groups in Puerto Rico have tried to teach people about these dangers using local media.

After a big wave in 2004 affected many countries around the Indian Ocean, more people became worried about what could happen in the Caribbean. Local leaders have started planning for emergencies. In Puerto Rico and the U.S. Virgin Islands, the United States government has been looking into these risks and is working on systems to give warnings about big waves.

Seismicity

On 11 October 1918, a strong earthquake hit the western coast of Puerto Rico, causing a wave that flooded the area. This earthquake happened because of an old fault near the Mona Passage. In 1953, a quake also affected Santo Domingo in the Dominican Republic. Experts worry because the main fault under the Puerto Rico Trench has not moved in over 200 years, and they think it might be ready for a big earthquake soon.

Puerto Rico often feels smaller tremors, showing that the area is active. For example, a tremor in 1981 was felt all over the island, and another in 1985 was felt in Cayey and Salinas.

The earthquake that happened on January 13, 2014, north of Puerto Rico, happened because of movements in the earth’s layers. Scientists think it moved either a shallow structure or a nearly upright one. At that spot, the North America plate moves slowly to the west-southwest compared to the Caribbean plate, and goes under it at the Puerto Rico Trench.

Exploration

Several trips to study the Puerto Rico Trench were done by scientists using special equipment on ships to map the ocean floor. In 1964, a French underwater vehicle named Archimède visited the trench for the first time, and in 2012, a robotic vehicle went down too. They saw many tiny creatures called amphipods living there, along with a soft dark animal that looked like a sea cucumber and a small crustacean.

American explorer Victor Vescovo went to the deepest part of the trench on December 19, 2018. He reached a depth of 8,376 meters using a special underwater vehicle called DSV Limiting Factor. This made him the first person to reach the bottom of the Atlantic Ocean. The area was surveyed by a support ship, and the information will help with mapping the world’s ocean floors.