What is Causing the 2018 Earthquake Swarm in the Comoro Islands?

The Comoros is a volcanic island chain of the coast of E. Africa that experienced an increase in seismic activity during May and June of 2018. A swarm of 81 magnitude 4.5 to 5.5 earthquakes were recorded on global seismometers. The earthquakes occurred east of the oldest island in the Comoros—Mayotte. The Comoros Islands are part of the East African rift system, but little is known of faulting and magmatism in this part of the rift. The overall goal of our research was to evaluate the time-space patterns of the earthquakes and possible causes of the earthquake swarm on Mayotte. The first thing we did was gather earthquake locations and magnitudes from the NEIC catalog. We then converted each magnitude value to Mw for consistent comparison of time and space variations. This information was then used to create figures that would help us determine the potential cause of the earthquake swarm. We analyzed the temporal and spatial patterns of the earthquakes in order to come to a final conclusion. From our results we were able to come to the conclusion that the swarm was not a result of a fault slip because the temporal patterns did not match Omori's Law because there was no clear mainshock-aftershock pattern. We compared the time sequence of earthquakes in Comoros with the patterns at actively erupting volcanoes: Kilauea, Hawaii and Sierra Negra, Galápagos. Our findings suggest that the earthquake swarm on the Mayotte island was a result of an eruption or intrusion on the eastern flank of Mayotte Island.