Week 5: Volcanoes

Currently, there are no active volcanoes in Puerto Rico and the Virgin Islands; the last volcanoes were active approximately 30 million years ago. The nearest volcano to Puerto Rico is Mount Pelée, an active stratovolcano near the northern end of Martinique, an island and French overseas territory in the Caribbean's Lesser Antilles Volcanic Arc. Its volcanic cone comprises stacked layers of ash and lava that have been cemented. 1932 saw its most recent eruption. It is considered the most active volcano in the Caribbean. At least four eruptions have occurred in the prior 250 years, including phreatic eruptions in 1792 and 1851 and, more recently, magmatic eruptions that produced lava domes in 1902–1905, 1929–1932, and elsewhere. Some mitigation efforts for Mount Pelée include creating hazard maps, studying the volcano, and creating a disaster plan in the instance that another catastrophic eruption occurs. When the volcano erupted in 1932, the post-disaster mitigation efforts included: bringing boats to remove survivors, evacuating the nearby towns, providing monetary support for the displaced people, and donations from all around the world. 

https://tourcrib.com/en/blog/vacation/martinique-volcano-pelee

https://volcano.si.edu/volcano.cfm?vn=360120

https://www.nsm.buffalo.edu/courses/gly433/pdfPowerPoint/Hanson.pdf

https://pages.mtu.edu/~gbluth/Teaching/GE4150/lecture_pdfs/L8_pelee.pdf

https://oceanexplorer.noaa.gov/okeanos/explorations/ex1811/background/geology/welcome.html#:~:text=There%20are%20currently%20no%20active,8%2C300%20meters%20(5.2%20miles).

Week 3: Earthquakes

Although Puerto Rico has historically had moderate seismicity, the territory is tectonically active, thus rare big earthquakes are to be expected. A total of 576 earthquakes with a magnitude of four or above have struck within 300 kilometers (186 mi) of Puerto Rico in the past 10 years. This comes down to a yearly average of 57 earthquakes per year, or 4 per month. On average an earthquake will hit near Puerto Rico roughly every 6 days.

 

The spread of seismicity southwest of Puerto Rico in December 2019 and January 2020 is depicted in the above graph. According to the time of the earthquake in relation to December 28, 2019, earthquake symbols are colored and sized by magnitude.

Seismic activity is depicted on the map above as orange circles and seismic monitoring stations as triangles. Recent upgrades to seismic stations are shown in red.

In order to avoid a catastrophic earthquake:

Through the Emergency Management Assistance Compact, the Commonwealth of Puerto Rico has asked the states of California and New York for help. The teams will offer technical support for building evaluations and inspections, as well as for the management and disposal of debris in the earthquake-affected districts.

The limited infrastructure evaluation, security/reconnaissance activities, evacuation support, and route clearance operations are all being helped by the Puerto Rico National Guard. To help, more teams are on their way.

Six temporary seismometers are being placed by the USGS along the coastline around the epicenters of the earthquakes. The ability to describe and anticipate earthquakes will be improved by data from aftershock monitoring devices.

As the complicated and ongoing recovery from Hurricanes Irma and Maria continues, FEMA continues to assist the government of Puerto Rico. It also works to ensure that everyone is better prepared for catastrophes that could affect the island at all levels.

References: 

https://www.usgs.gov/news/featured-story/magnitude-64-earthquake-puerto-rico

https://www.fema.gov/press-release/20230425/fema-and-other-federal-agencies-supporting-earthquake-response-puerto-rico

https://earthquakelist.org/puerto-rico/