Earthquakes

On May 28 2009 at 2.25am local time an earthquake of 7.3 magnitude occurred off the northern coast of Honduras, about 80 miles from La Ceiba, where Drew students were staying as they volunteered at Helping Honduras Kids (HHK) in nearby Agua Caliente. A second quake measuring 4.8 followed 42 minutes later slightly west of the first, and additional quakes of 4.5 and 4.6 occurred on the same fault line at 8.45pm local time and 6.51 am local time on May 29th (see the U.S. Government Geological Survey website for information about the quakes, and maps, and USGS NEIC for a list of all recent quakes). The quakes occurred about 6 miles below the ocean floor, and a tsunami watch was announced after the first quake, but quickly canceled. There were some power outages and email was down in many areas, but cell phone signals worked and the group reported no significant damage in La Ceiba or the surrounding areas.  Seven deaths were reported overall, mostly as a result of falling trees and several bridges were damaged but it was determined that the students were not at risk and the trip continued. (See the L.A. Times for news coverage–there is basically one story that is being recycled in many media.)

Honduras is bordered on the north and south by fault lines, and small earthquakes are not unusual as the plates move and settle. Prior to 2009, the last big earthquake in Honduras occurred in 1999 close to the site of the 2009 quake. That one measured 6.7 and occurred at about the same depth below the ocean floor. Both quakes–and many of the other earthquakes in Honduras, were on the Swan Island fault, which is the very steep southern boundary of the more than 5000 meter deep Cayman Trough.  Read more–and track earthquakes–at the US Geological Survey website. Learn more in a Geology class!

Why did the quake in Haiti do so much more damage even though it was smaller in magnitude than the Honduran quake? Good question. First, and most significant, the epicenter of the Haiti quake was only a few miles from the city of Port-au-Prince rather than below the ocean. There have been claims that the quality of construction, and especially the cement used in Haiti was poor (similar claims were made to explain the extensive damage to schools after the earthquake in Sichuan Province, China, in May 2008). This matter will be investigated. But it is true that buildings in Honduras are quite sturdy. In early November 1998, Hurricane Mitch destroyed most of the buildings that did not have strength to withstand natural disasters. Much of the massive rebuilding that occurred after Mitch was funded and executed by foreign countries and workers–including Drew students. If the buildings we worked on are typical, they are much more likely to withstand a strong quake than the buildings they replaced. They withstood devastating storms in October 2008, and the earthquake in May 2009.

Hopefully we will never experience another quake in Honduras, but we are encouraged by the 2009 experience.