Earthquake Scenarios for Puerto Rico
Earthquakes are unsettling, destructive, and often tragic to the communities they affect. The USGS works diligently to help keep people safer by providing them and their emergency responders the science needed to respond to ongoing hazards.
Last updated April 27, 5pm Pacific time, 2020.
There will be no further updates. Please see the Aftershock Forecast.
About the scenarios
Here are the three most likely scenarios for how this earthquake sequence will evolve over the next 30 days based on our aftershock forecasts. These scenarios describe three possibilities of what could happen from March 18 to April 18. Only one of these scenarios will occur within the next month. These scenarios will change over time, like our forecast.
The earthquakes in these scenarios would occur in the areas where aftershocks are happening now. Earthquakes in this sequence will continue to occur for days, months, or potentially years to come. It is very unlikely the aftershocks will cease completely within the next month.
Scenario One (Most likely): 98 percent within the next 30 days
The most likely scenario is that aftershocks will continue to decrease in frequency over the next 30 days and will be significantly lower in magnitude than the M6.4 that occurred on the 7 January 2020 (i.e., will be less than M6.0). Some of these moderately sized aftershocks (M5.0+) may cause localized damage, particularly in weak structures. Smaller magnitude earthquakes (M3.0+), when at shallow depth, may be felt by people close to the epicenters.
Scenario Two (Less likely): 2 percent within the next 30 days
A less likely scenario is an earthquake occurring of similar size as the M6.4 event. This is called a “doublet”: when two large earthquakes of similar size occur closely in time and location. This earthquake could cause additional damage in the same region and increases the number of aftershocks.
Scenario Three (Least likely): <1 percent within the next 30 days
A much less likely scenario than the previous two scenarios is that recent earthquakes could trigger an earthquake significantly larger than the M6.4 that occurred on the 7 January (i.e., M7.0 and above). While this is a very small probability, if such an earthquake were to occur, it would have serious impacts on communities nearby. This size earthquake would also trigger its own aftershock sequence, so the rate of small and moderate earthquakes would increase again.
For More Information
Eventpage with Earthquake Details