Images

Map of the portion of the southwest coast of Puerto Rico affected by an earthquake sequence that began in December 2019, along with portions of the seafloor where faults involved in the earthquake sequence were suspected to exist.

Locations of multichannel seismic reflection profiles (in black), collected during cruise FA2020-14. The profiles are overlain on colored and shaded multibeam bathymetry, Lidar topography (green and white) and near-shore bathymetry (darker blue), and NOAA coastal relief model (light blue and white).

USGS marine technician Wayne Baldwin prepares to deploy the hydrophone array during a seismic research cruise off the southwest coast of Puerto Rico on board the R/V Sultana in March 2020.

USGS marine technicians Alex Nichols (L) and Eric Moore (R) deploy the hydrophone array on a seismic research cruise off the southwest coast of Puerto Rico aboard the R/V Sultana in March 2020.

USGS research geologist Jason Chaytor (L) and marine technicians Alex Nichols (center) and Eric Moore (R) deploy the “sparker” sound source on a seismic research cruise off the southwest coast of Puerto Rico aboard the R/V Sultana in March 2020.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a landslide failure along a residential road in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a lateral spread along a residential road in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a lateral spread near a stream in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a lateral spread near a stream in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. The boardwalk in Ponce, Puerto Rico was damaged by the quake.

Meet the team of USGS scientists who were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. This landslide was discovered along a neighborhood road near Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. This landslide was discovered along a neighborhood road near Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a rockfall damage to a house in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of rockfall material in the yard of a house in Ponce, Puerto Rico.

USGS scientists were deployed to assess land deformation and movement after a large M6.4 earthquake struck Puerto Rico on January 7, 2020. Here is an example of a lateral spread near a stream in Ponce, Puerto Rico.