Accurate Earthquake Data A Met Challenge As Samoa Gets 5.9 Magnitude Shake

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  • Fuimaono Lameko Talia with Silipa Mulitalo of MET Division
    Fuimaono Lameko Talia with Silipa Mulitalo of MET Division

 

A 5.9 earthquake shook Samoa on Friday night with the centre at about 150 miles south-southwest of Apia with no reports of any serious impacts.

The United States Geological Survey (USGS) estimated the quake struck at a depth of 10km.

Earthquakes are a concern for the Meteorological Division of the Ministry of Natural Resources (MNRE) struggling for data to make accurate predictions.

The concern was raised during the National Environment Week organised by the MNRE.

 Fuimaono Lameko Talia Principal Scientific Officer For Geoscience Division of the Meteorological Section of the Ministry of Natural Resources and Environment MNRE said that their office is doing everything they could do with the equipment they have to get accurate predictions but they would like more up to date technology and equipment.

He reflected on the improvement already made since the 2009 tsunami, which was triggered by an 8.1 magnitude earthquake. The tsunami killed more than a 100 people.

He said that at the time the tsunami occurred they had to rely on the sole assistance of the seismic station by the US Geological Survey for data. But since then a lot of improvement has been made.

"Because of that 2009 tsunami, we were able to ask for assistance for seismic stations so that we can have better data. Before that, we only had one station and that was by the U.S. Geological Survey and that station was manually operated. Now we have 6 automatic stations and so as soon as the earthquake happens, the stations send us data in less than one minute so we're able to analyze, digitize and send the message to the people in less than 2 minutes and that's the benefit of having automated stations." Fuimaono explained.

Fuimaono said more stations are needed and these need funding and that is now more pressing with Samoa experiencing frequent earthquakes. Moreover, Samoa is more vulnerable to earthquakes with its close location to the Samoan Tongan Trench.

"We have quite a lot of earthquakes in Samoa. The area we are worried about is the Samoa-Tongan Trench (at the tip of the massive Tongan Trench up north) there are quite a lot of earthquakes coming from that area. About 90% of all of our earthquakes come from that area as well as the 8.1 earthquake in 2009 came from which killed many people."

"So we need to see more accurate data, better instrumentation, better warning procedures. We need to improve on those things and also realizing we used to rely on one seismic station, now with 6 automated stations, there is a benefit of having more as it helps us pinpoint exactly where the earthquake comes from, all these stations pick on one spot and they all point to one place.”

Getting the right data, help provide future predictions on the occurrence of major earthquakes.

"There was a 7.4 earthquake in 1981 which flooded the Manono Island and that is very close to Savaii and given the return period of about 76 years for large earthquakes and we are looking at about 20-30 years to expect another 8.1 earthquake around the same time on the Southern side of Savaii and we need to be prepared for that."

Fuimaono pointed out that data is very important as they tell a story.

"There is a story behind the data and the good thing we know about data is that we know which one is the big one, and where it comes from and where is the favorable area for the earthquake to happen."

With the close proximity of the Samoan-Tongan trench Fuimaono said, it only takes 10 minutes for the country to evacuate and that is a major concern!  

"In those 10 minutes, you don't have time to muck around but to back up and leave."

Fuimaono expressed appreciation of the Chinese Earthquake Administration Office for funding Phase One of the Samoa-China Seismographic Phase 1 after the 2009 tsunami and aiding the 6 seismic stations.

He added that in the pipeline, is talks for Phase Two of the project that will assist in provision of the right instrument and the right computers to analyze data and also help the Samoan team to explore field work and place GPS in areas where evidences of faults which causes movements of the ground from time to time.

Fuimaono said that it cannot be denied that big earthquakes will happen and it is important that the people are given the information.

 

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