The people of Solomon Islands started their Thursday with a series of earthquakes. The largest earthquake in the series measured 6.8 in magnitude on the Richter scale and struck off the coast of the Solomon Islands on May 21. It was followed by two smaller earthquakes measuring 4.9 and 4.6 in the same region. The largest quake struck at 9:48 a.m. local time on the Solomon Islands, and was followed by a 4.9 temblor at 10:01 a.m. and the 4.6 temblor at 10:19 a.m. All three were mostly shallow quakes and happened underwater.
All the earthquakes, which hit the Solomon Islands, were centered near the Santa Cruz Islands, a group of islands 250 miles southeast of the Solomon Islands chain, but still a part of the country. The 6.8 quake was 303 miles away from Honiara, which is the capital of the country and 114 miles west of Lata, the nearest city. There have been no reports of casualties or structural damage. The 4.9 temblor was 273 miles away from Honiara and 123 miles southeast of Kirakira, while the 4.6 was 298 miles from Honiara and 116 miles west of Lata.
The U.S. Geological Survey, which monitors and tracks all earthquakes, said that the largest temblor hit at a depth of 12.3 miles. Of the series of earthquakes, only the 6.8 caused some concern about a probable tsunami warning in the Solomon Islands area, which was soon squashed when the Pacific Tsunami Warning Center issued a statement that a tsunami was not expected. They also said that there is no tsunami threat to Hawaii. The largest temblor was also the nearest to the neighboring island nation of Vanuatu, whose capital, Port-Vila, was 547 miles from the epicenter.
The Solomon Islands are part of the Pacific Ring of Fire, and it lies on the eastern margin of the Australian plate. It is one of the most seismically active areas in the world and there have been 15 earthquakes, over 7.5 in magnitude, recorded in the region since 1905. Volcanoes–some dormant and some still active–are located on several of the larger islands of the Solomon Islands archipelago. Kavachi, a submarine volcano, is the most active underwater volcano in southwestern Pacific Ocean. Another volcano, Tinakula, last erupted in 2007 and is located on an uninhabited island. Any mid-level earthquake in the region is in danger of causing a tsunami and volcanic activity.
The island country is home to approximately 600,000 people. It has felt earthquakes as large as 8.1 on the Richter scale in 2007. This was followed by a tsunami which killed 52 people. A 2013 earthquake, which measured 8.0, killed at least 9 people. The island nations in the South Pacific are also recovering from Cyclone Pam, which was the worst natural disaster ever to have struck Vanuatu. In the Solomon Islands, the storm flattened crops, trees, and homes were destroyed. During the buildup of the cyclone, heavy rainfall also caused extensive damage to real estate. Tikopia, which is a small island in the Solomon Island archipelago, lost 90 percent of its food crop.
The region of Papua, New Guinea, which includes the Solomon Islands and Vanuatu, has been unusually active, according to geologists, resulting in a series of minor earthquakes and aftershocks. Earlier this month, a quake measuring 7 on the Richter scale had struck the region. It had triggered a tsunami warning briefly in Papua, New Guinea and the Solomon Islands, but nothing happened and it did not result in any casualties. It followed two other quakes measuring 7.4 and 7.7 in magnitude in the previous weeks. All of them caused no loss of human life.
By Anugya Chitransh
Pacific Tsunami Warning Center: Message hawaii.TIBHWX.2015.05.20.2256
USGS: M6.8 – 184km W of Lata, Solomon Islands
USGS: M4.6 – 187km W of Lata, Solomon Islands
USGS: M4.9 – 198km ESE of Kirakira, Solomon Islands
Photo Courtesy of Jenny Scott’s Flickr Page – Creative Commons License