Monday 6 July 2015
Tsunami watch alert cancelled after 8.6 earthquake and aftershock off Indonesia thumbnail

Tsunami watch alert cancelled after 8.6 earthquake and aftershock off Indonesia


An Indian Ocean-wide Tsunami Watch Bulletin was issued on Wednesday afternoon by the Pacific Tsunami Warning Centre after an earthquake measuring 8.6 on the Richter scale occurred off the coast of Indonesia, followed by an aftershock measuring 8.2 almost two hours later.

The Centre revised its initial update after sea level readings confirmed a “significant” tsunami was generated, and subsequently cancelled the warning five hours after. Any tsunami was predicted to hit the Maldives at 11:49(GMT) – 16:49 Male time, and 11:44(GMT) – 16:44, the Centre reported, but advised that waves could follow for up to two hours after this period. The first wave may not be the largest and further waves could follow in intervals of five minutes to one hour.

The Centre said that the initial shock generated a tsunami measuring 17 cm (6.7 inches), and advised authorities to “take appropriate action”

Such an earthquake had the potential to “generate a widespread destructive tsunami that can affect coastlines across the entire Indian Ocean basin”, according to the centre’s initial report.

Alerts were issued by the Maldivian meteorology department, which extended its alert period by two hours to 7:30pm, following the aftershock.

Residents in the capital Male’ reported feeling tremors with bottles and glass shaking when the first earthquake struck. Several tall buildings, including the government building Velanaage, and schools, were evacuated earlier this afternoon.

Tremors were also reported in the Indian cities of Kolkata, Chennai, Bangalore, Kochi and Thiruvananthapuram.

Bruce Presgrave of the US Geological Survey (USGS) told the BBC that the nature of this quake made it less likely a tsunami would be generated, as the earth had moved horizontally, rather than vertically, therefore had not displaced large volumes of water: “We can’t rule out the possibility, but horizontal motion is less likely to produce a destructive tsunami,” he said.

The 2004 tsunami inundated entire islands in the Maldives, but only caused minor damage in capital city Malé. The northern sea wall and buildings on city’s seafront were damaged. The waves caused minor flooding as well.

Minivan News will provide updates as the situation develops.

UPDATES:

14:30 – According to the BBC, the US Geological Survey has reported that the quake at Aceh quake was centred 33km (20 miles) under the sea about 495km from Banda Aceh.

14:35 – Offices, school and governent buildings in Male’ and Hulhumale’ were evacuated as the people felt the tremors.

14:40 - MET Director Hussain Waheed told state broadcaster: “There is a potential tsunami risk to the Maldives in next two or three hours. But there has been no sign of a tsunami yet. However, he advised the people to be on alert.

14:52 – Deputy Tourism Minister Mohamed Maleeh Jamal told Minivan News that government bodies were now following the instructions of the coast guard and Maldives National Defense Force (MNDF). Resort management had been formed and the government was set to form its crisis management committee established following the 2004 Asian tsunami that struck many islands across the Maldives.

Jamal said he himself had been in the Velaanage Building, where he said that tremors as a result of the quake could be felt.

“All government employees in the building were evacuated to ground level,” Maleeh said of the situation at the time. “We are still waiting for exact details on the situation, but we are working with the military and coast guard.”

Report from the Pacific Tsunami Warning Centre:

“EARTHQUAKES OF THIS SIZE HAVE THE POTENTIAL TO GENERATE A WIDESPREAD DESTRUCTIVE TSUNAMI THAT CAN AFFECT COASTLINES ACROSS THE ENTIRE INDIAN OCEAN BASIN.

HOWEVER – IT IS NOT KNOWN THAT A TSUNAMI WAS GENERATED. THIS WATCH IS BASED ONLY ON THE EARTHQUAKE EVALUATION. AUTHORITIES IN THE REGION SHOULD TAKE APPROPRIATE ACTION IN RESPONSE TO THE POSSIBILITY OF A WIDESPREAD DESTRUCTIVE TSUNAMI.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES AT FORECAST POINTS WITHIN THE WARNING AND WATCH AREAS ARE GIVEN BELOW. ACTUAL ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN SUCCESSIVE WAVES CAN BE FIVE MINUTES TO ONE HOUR.”

15:07 – Mobile networks are suffering from congestion due to a sudden spike in usage, report major providers.

15:11 – Government spokesman Abbas Adil Riza said the Maldives was evacuating beaches. The National Disaster Management Centre is continuing to issue updated warnings and assess any potential threat: “Right now, we are seeing if there is a threat [from today’s Indonesian earthquake] to this side of the Indian Ocean.

15.18 - David Cameron tells Indonesian President that he is ‘hugely concerned’ about the earthquake, reports the BBC.

15:25 - Bruce Presgrave of the US Geological Survey (USGS), has told the BBC that the nature of this quake made it less likely a tsunami would be generated, as the earth had moved horizontally, rather than vertically, therefore had not displaced large volumes of water: “We can’t rule out the possibility, but horizontal motion is less likely to produce a destructive tsunami,” he said.

15:42 - Maldives National Defence Force (MNDF) spokesperson Colonel Abdul Raheem has said that no signs of a tsunami wave within the Indian Ocean have as yet been identified.

“At the moment we are monitoring areas around the country, but have not observed any tsunami,” he said. “We have been in contact with other countries like Sri Lanka and India and they have said the same thing.” Raheem concluded that at present, the Indian Ocean remained calm.

15:44 – Indonesia’s disaster management agency said power was down in Aceh province and people were gathering on high ground as sirens warned of the danger. “The electricity is down, there are traffic jams to access higher ground. Sirens and Koran recitals from mosques are everywhere,” said Sutopo, spokesman for the agency.

The quake was felt as far away as the Thai capital, Bangkok, and in southern India, residents said.

15:49 – Reuters news agency, quoting tsunami warning centre official, has reported the total vertical measurement of the tsunami wave, according to monitoring gauges, was 35 cm (13.8 inches), making the height 17 cm (6.7 inches).

“It doesn’t look like a major tsunami,” Victor Sardina, a geophysicist on duty at the Hawaii-based Pacific Tsunami Warning Centre said. “But we are still monitoring as tsunamis come in waves.”

16:14 - The Centre revised its initial update and said that if generated, the tsunami was likely to hit the Maldives at 11:49(GMT) – 16:49 Male time, and 11:44(GMT) in Gan local time 16:44

16:16 – Sea level reading confirm a tsunami was generated, reports the Pacific Tsunami Warning Centre.

16:21 – Met Office Director Hussain Waheed has said that the country has not decided to updated the severity of its warning since the tsunami warning was first raised earlier this afternoon, but will be extending the period of the tsunami watch for at least an hour and a half.

The Met Office said it continues to issue a yellow bulletin, which requires authorities to keep a watch on potential tsunami development.

“Any earthquake of a  magnitude of over 8.0 results in a yellow bulletin being issued,” he said.

With the yellow bulletin in place, Waheed said that the Met Office would be continuing to run a tsunami watch regarding the situation in the Maldives for at least the next hour and a half due to aftershocks that have occurred in Indonesia.

16:25 – The latest (4th) bulletin from the Pacific Tsunami Warning Centre advises that when no major waves have occurred for two hours after the estimated arrival time (16:49 for Male, 16:44 for Gan, local time), authorities can assume the threat is passed.

“Danger to boats and coastal structures can continue for several hours due to rapid currents. As local conditions can cause a wide variation in tsunami wave action the all clear determination must be made by local authorities.”

16:29 – UNICEF worker Edward Carwardine in Jakarta, Indonesia, told Al Jazeera: “People are quite rightly moving to higher ground, moving away from the coastal areas as fast as they can. I think it’s an indication of how much people have learned from the terrible experiences of a few years ago. We haven’t yet heard of things like structural damage … right now people are looking after themselves and that’s the best thing they can do.”

16:30 – The 2004 tsunami inundated entire islands in the Maldives, but only caused minor damage in capital city Malé. The northern sea wall and buildings on city’s seafront were damaged. The waves caused minor flooding as well.

Following the Indonesia geophysics agency’s extension of a tsunami warning in Aceh province, the Pacific Tsunami Warning Centre has issued a new warning for the Indian Ocean following aftershocks off the Indonesian coast.

16:35 – The Maldives MET Office has extended the alert for Maldives until 5:30pm local time, following the latest after-shock which measured 8.2 on Richter scale.

16:46 - The Tourism Ministry activated its disaster management policy at 14:15 today, Minister Ahmed Adheeb has said on Twitter. All resorts were informed, tourist recalled to the island and head counts taken.

16:25 – Trans Maldivian Airlines (TMA) Managing Director Edward Alsford said the company is not making any changes to its scheduled activites at the moment. He said that the company did have back up systems in place when necessary. At the moment the sea plane operator was taking a precautionary stance while awaiting further information, he said.

16:45 – Ibrahim Nasir International Airport (INIA) CEO Andrew Harrison has said that management were currently monitoring the situation as it developed at the airport, and enacting countermeasures to protect vehicles in the event of a tsunami.

Harrison added that airport management was currently talking to sea plane operators and other airline operators to potentially move some aircraft to protect against any adverse impacts from a tsunami or irregular tidal pattern.

16:54 – People from coastal areas in Indonesia have been evacuated, police have told an Al-Jazeera correspondent. There are no reports of damages or casualties.

16:57 – India’s National Disaster Management Authority (NDMA) has played down tsunami reports in the region. The organisation had initially issued a warning for Andaman and Nicobar Island, and an alert to coastal areas of Andhra Pradesh and Tamil Nadu.

“There is no specific threat. It was a watch and alert. There is no likelihood of any tsunami in the Indian Ocean region,” NDMA Vice President Sashidhar Reddy told the Press Trust of India.

“It is the kind of strike and slip earth quake which does not trigger tsunami. There was no vertical displacement of water under the sea,” he said. “Tsunami possibility is virtually ruled out.”

17: 10 – The tsunami alert period has been extended in the Maldives to 19:30 local time, reports Haveeru.

17:13 – Safari boat operator Danielle Clayton, currently on her vessel in Dhaalu Atoll, said that she and her crew had not experienced any adverse conditions since the country issued a tsunami warning this afternoon.

“We first found out about the situation from Facebook, but since then we have come into the atoll with a number of other [live-aboard] boats,” she said.

Clayton added that they had been visited by the coastguard and remained in touch with other vessels for updates on the situation.

“Our crew are local guys and they have been getting in touch with people too.”

17.15 - Director General of the Department of Meteorology, Hassan Waheed, has confirmed that due to the aftershock the tsunami warning has been extended until 7.30pm local time.

17:16 – The airport has issued a statement noting that a tsunami watch “means there is the potential for a tsunami, not that one is imminent”. The airport continues to be on amber alert and “all seafarer vessels are advised to keep distance from the jetties and moor in the mooring areas located in the outer harbour area.

17:23 – The Pacific Tsunami Warning Centre has issued a fifth notification following the earthquake, scaling back the tsunami watch area to Indonesia, India, Sri Lanka, the Maldives and Diego Garcia. Estimate arrival times for a tsunami in the Maldives have now passed, but the watch period continues for two hours past the estimate (11:49GMT/16:49 local for Male’, and 11:44GMT/16:44 local for Gan).

17:29 – Indonesia’s Jakarta Post reports “small tsunamis” reaching upto 80 centimeters high have hit Meulaboh and Sabang cities in Aceh.

17:59 – The Pacific Tsunami Warning Centre has cancelled the tsunami watch alert for both the 8.6 earthquake at 1339 Male time, and the 8.2 aftershock at 1543. “Sea level readings now indicate that the threat has diminished or is over for most areas”, the centre reported.

19:45 - Director General of the Meterological Department confimed the cancellation of the tsunami watch saying: “The danger has passed. The wave was recorded mostly affecting Indonesia. There was only a small rise in our tsunami gauge.”

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