‚ÄčThe January 2010 Solomon Islands Region Earthquake

Map #1 Topographic map of area

On Tuesday January 5, 2010 the Solomon Islands were struck with a magnitude 7.2 earthquake south-south east of Gizo at 10:37 A.M (see figure 2). This followed a 6.6 magnitude foreshock centered 36 km south east of Rendova at 8:48 A.M. According to the Pacific Tsunami Warning Center in Hawaii, no tsunami warnings were issued.
Figure 2 - Intensity Map (source #4)
The earthquake in fact triggered a tsunami with a 10 foot high wave, and two landslides which were luckily in remote areas of the islands. Rendova is home to only 3,600 people. Officials estimated that 1,000 people had been affected by the event and approximately 200 homes were destroyed, seaside communities were affected the most. No deaths or serious injuries were found to have come from the quakes, the tsunami, or landslides. Small aftershocks continue to occur on the islands, the largest being a 5.2 on January 18th. The quakes were centered beneath the ocean floor at depths of 33 km to 36 km, which is approximately 20.5 miles. According to the University of Portland seismometer (OPOR), Portland is located 9,919 kilometers from the location of the earthquake. After the 7.2 earthquake, it took 12 minutes and 53 seconds from the P-wave to travel a path through the mantle from the Solomon Island to Portland. S waves arrived 23 minutes and 41 seconds after the earthquake. On January 15th, 2010, there were many issues that had to be dealt with because of the earthquake. Some of these issues were landslides, flash floods, damages schools, water contamination and reports of diarrhoea, red eye, the flu and coughing. The water contamination could be carrying giardia or parvo, which leads to diarrhoea and other sicknesses. Schools were closed but where to open again on January 18th. Temporary school shelters were put up so the children could continue their educations. These temporary classrooms were tents.

Lessons Learned From Previous Earthquakes

The Solomon Islands are considered part of "The Ring of Fire", described as an area where colliding continental plates cause seismic, earthquake activity, volcanic zones that stretches around the Pacific Rim, about 90% of the world's quakes occur here. Because of the the Islands have seen their fair share of earthquakes over the years. In recent years, several research investigations have been undertaken in the region to help understand present processes of subduction, accretion and fragmentation of oceanic plateaus at subduction zones and their deformational effects on the overriding Solomon island arc. The researchers are looking at different models of tectonic interaction. For example, one of the models postulates wedging of the Solomon Island Arc beneath the Ontong Java plateau, the largest oceanic plateau in the world, Northeast of the Solomon Islands. The other model postulates an oceanic accretionary wedge geometry with northeastward component towards the Ontong Java plateau. The most devastating in recent years has been the 8.1 magnitude earthquake which occurred on April 2, 2007 south-south east of Gizo. An 6.5 foreshock occurred less than one hour before this main shock, centred 90 km southeast of Gizo at a depth of 10km. The earthquake caused a devastating tsunami which took the lives of 52 people in the western and Choiseul Provinces. With this recent earthquake came unhappy memories for so many people, of lost loved ones. Even though there were no official tsunami warnings people listened to the advice of the National Disaster Management office and moved to higher ground. Another reason that the quake and tsunami spared lives was because the events happened in the daylight, the landslides were in sparsly populated areas, and the wave was isolated. One resident, a dive shop owner named Danny Kennedy, said that the general rule followed by locals is; "If there is more than 20 seconds of shaking, or any water recedes, head for the hills"

Works Cited
"Earthquakes in the Solomon Islands, Pacific Ocean : Image of the Day." NASA Earth Observatory : Home. Web. 16 Mar. 2010. <http://earthobservatory.nasa.gov/IOTD/view.php?id=42176&src=iotdrss>.
"Shakemap Us2010rabw." U.S. Geological Survey Earthquake Hazards Program. Web. 15 Mar. 2010. <http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/2010rabw/>.