U.S. GEOLOGICAL SURVEY graphic The inferred rupture area (white dashed line) of the May 4 magnitude-6.9 earthquake, with its foreshocks and first 10 days of aftershocks, spans an area of about 800 sq km (300 sq mi). Circle size indicates earthquake magnitude; color indicates earthquake depth. Magnitudes for some of the larger events are labeled. Inset graph shows the aftershock decay rate for May 4-15.
On May 4, a powerful magnitude-6.9 earthquake on the south flank of Kilauea Volcano shook the Island of Hawaii. It was the largest quake in Hawaii in 43 years. Today, more than five months later, smaller-magnitude earthquakes in the same area are still occurring.