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Appendix E -  Seismic & Other Risks
 
Security
The recent history of the target areas for ISLAND-AID's ICS programs has area specific security issues that require careful management to ensure that our field teams are able to work at maximum efficiency in safety and with as much comfort as is practical in the field.
Environmental Security
Seismic Activity
Using GPS monitoring and stress modeling seismologists believe that a major seismological event is imminent off the coast west of Padang. Research by eminent seismologists Kerry Sieh and John McCloskey has indicated that an earthquake in the Mentawai Island area is possible within the next 12 months  

Historically the Mentawai region has experienced major earthquakes and tsunamis every 200-230 years. 172 years have past since the 1833 quake, and 208 years since the 1797 quake. The huge movements over the past 6 months may bring the next event forward. An earthquake will cause a great deal of destruction, but a tsunami off the coast of Padang has the potential to cause the same scale of destruction as seen in Aceh.

The municipal council of Padang has introduced a Tsunami and Earthquake Information Post that provides current information on earthquake threats. It has also developed a map that shows the potential tsunami danger area and a series of escape routes from each part of the coastline. This will prevent mass congestion out of the lowlands in the event of an earthquake or tsunami. Continued reference to current information such as this will enable ISLAND-AID to maintain an adequate and adaptable security policy with regard to environmental safety.

Given that the majority of ISLAND-AID operations will be conducted from a vessel at sea, the impact of another earthquake or tsunami would be minimal. Similarly, the Padang headquarters withstood the recent series of earthquakes with no damage and is located 275 m above sea level. Another earthquake or tsunami could have major impact on the city and surroundings but would have minimal impact on safety at ISLAND-AID facilities.

All volunteers are briefed on earthquake and tsunami risks and appropriate action should a major seismic event occur while in the field, on a ship or boat, in the city or at headquarters. Battery powered emergency lighting is installed in all buildings used by volunteers and staff so that exit at night during a power failure is safe and orderly.
What drives tsunamis in West Coast Sumatra
Wet Season and Monsoon Swell
North Sumatra does not have a clear cut wet season, with high rainfall recorded throughout the year; although there is an increase in average rainfall from September to December. The weather in this period is consistent with torrential rain capable of washing away roads, flooding rivers and triggering landslides. Flooding is a grave risk due to the significant subsidence caused by the earthquakes along the NW Aceh coast. In other areas debris has choked rivers and makeshift bridges are under threat of collapse when ever heavy rains create log dams upstream of these low lying structures. Many mountain communities will now be vulnerable to landslides as demonstrated by the June landslide in Nias which buried half a village and killed 4 people. Working from a vessel at sea overcomes most of these issues.

ISLAND-AID's Padang Headquarters is built on bedrock and at the top of a hill engineered to minimize the risk of soil movements and an all weather road leads to the harbor area and fuel stations.

ISLAND-AID has secured the long-term support of Argoss NL who provides sophisticated wind and swell forecasts daily to ISLAND-AID's website. 5-day projections of deep ocean swell are of great value when planning beach landings on exposed coasts.
Disease Outbreaks
Given the large number of IDP living in large camps and the number of persons yet to receive adequate medical attention there is the potential for a disease outbreak. These have been largely kept to a minimum, with only one report of a malaria outbreak in Meulaboh. However, the wet season is yet to commence in earnest, which will increase the risk of disease.

During missions ISLAND-AID volunteers will reside on the Electric Lamb and will have access to potable water, refrigeration and clean food preparation areas. ISLAND-AID  volunteers will also be briefed in and have access to universal protection measures, such as gloves, face masks and sterilized equipment, for the provision of medical assistance. For a specific disease outbreak, ISLAND-AID will take any additional precautions as required. In addition, all volunteers will be required to have the necessary vaccinations for the area of operations and be taking anti-malarial drugs. As such, while a disease outbreak would be serious, the impact on ISLAND-AID operations would be negligible.

ISLAND-AID normally has in-house medical capacity with either trained volunteers or partner NGO medical staff available to assist team members. All volunteers are advised to take out medivac and travel insurance prior to arrival in Indonesia.
Scientists Voice Tsunami Concern
by Electric Lamb Mission on Friday, December 9 @ 8:40 AM


By Jonathan Amos
BBC News science reporter, San Francisco

A US scientist studying the islands off southern Sumatra says it is very clear the region can expect more big quakes and tsunami in the coming decades.

Prof Kerry Sieh is using a GPS network to monitor land movements close to the great fault line that ruptured to produce last December's disaster. His work indicates there is still huge strain bound up in the fault, and that this could let go in the near future.

He believes the cities of Padang and Bengkulu may be at greatest risk.

"The time is now to start mitigating for such an event," said Kerry Sieh, who is attached to the California Institute of Technology's Tectonics Observatory.

"I don't know with certainty that it's going to happen but our team is telling people on the coast that they have to expect that this will happen in the lifetime of their children." ( Sieh has recently revised this to a 20 year period based on GPS monitoring of control points in the area. Ed)

To the south
The 26 December quake of magnitude 9.2 stemmed from a rupture along the line where the Indian/Australian and Eurasian tectonic plates grind over each other.


Coastal trees are being submerged as the strain accumulates

The associated tsunami wrought destruction throughout the Bay of Bengal, from Northern Sumatra to Thailand, Sri Lanka, and India. It was followed by a magnitude 8.7 in March - with the rupture occurring further south along the plate boundary.

Prof Sieh, speaking here at the American Geophysical Union Fall Meeting, says the concern of scientists is now focused on events further south still, to a region known as the Mentawai islands patch. This zone has experienced giant earthquakes about every two centuries, and is nearing the end of its earthquake cycle.


Coral rise
Prof Sieh says the strain building up in the region is evident from the behaviour of island coastlines - some are becoming submerged. It is in the nature of tectonic plates that they do not glide smoothly past each other, as one dives under the other.

After a quake, land that had been pulled down will pop back up
In fact, the plates move in "stick-slip" fashion, which means land at the leading edge of the overriding plate is pulled down briefly before suddenly slipping back up, generating a large earthquake.

Surveys along northern Sumatra following the 26 December and 28 March events have revealed coral reefs that have come out of the water as land has thrust back up.

"When you look further to the south, the groves of trees and other coastal features are still sitting out in the water; they have not yet risen. So, we know the strain is still accumulating; our GPS network is telling us it is still accumulating," Prof Sieh explained.
"Our concern is that the next thing to happen will be ruptures."

Wave model
Prof Sieh says historical and coral records show the Mentawai islands patch experiences magnitude 8-plus quakes on a roughly 200-year cycle, and are accompanied by large tsunami.
"It appears that these giant earthquakes either occur singly or in couplets: singly in the 1300s and late 1500s, and as a couplet in the late 18th Century and early 19th Century; and the average time between those three sets is about 240 years."


Modelling predicts up to 10m waves hitting the coast
Prof Stephan Grilli, from the University of Rhode Island, has modelled the tsunami that would result in the area from a magnitude 9.2 quake, the same as 26 December.
"Our prediction for Padang and Bengkulu further south would be up to 10m waves hitting the cities," he told the AGU meeting.

Both Padang and Bengkulu are bigger cities than Banda Aceh which was destroyed in the 26 December tsunami.

Like Banda Aceh, Padang is very low-lying.
Time Magazine Article - "Living on a Fault Line"
Time Magazine's "LIVING ON A FAULT LINE"
by Island Aid on Wednesday, February 1 @ 12:32 PM


JOHN STANMEYER—VII FOR TIME
HELPING HANDS: Geologist Sieh, center, explains tectonic plate movements to local residents

How frightened should we be?

http://www.time.com/time/asia/2005/disaster/story.html

Posted Monday, December 12, 2005; 20:00 HKT

The village of Maligi (name changed to avoid panic) on the west coast of the Indonesian island of Sumatra seems idyllic—two dozen houses strung along a palm- and casuarina-covered strip of land, on one side the crashing waves of the Indian Ocean, on the other a rippling river mouth. When a rare group of visitors appears in the bright mid-morning sunlight, a dozen children chase after the car, laughing and waving.
"So many kids," American geologist Charles Rubin mutters gloomily as he waves back. "They don't have a chance."
"Nope," agrees fellow geologist Kerry Sieh, also waving and smiling. "They'd all be killed. There's just nowhere to run here. It's water on both sides."
"If they knew what was coming, they might be able to climb the coconut trees and survive," Rubin continues, "assuming the tsunami wasn't too high, say in the four-meter range. They need to build platforms on the trees and maybe cut steps in the tree trunks. They need information. You should give them one of your posters, Kerry."
Sieh nods. A professor of geology at the California Institute of Technology, he probably knows more than any person on the planet about how and why earthquakes and tsunamis happen so often, to such deadly effect, in this part of the world. Sieh and his colleagues on this field trip know how many lives have already been saved by posters and other efforts to educate those who live in a 2,000-km-long danger zone running from Aceh on the northern end of Sumatra to an island off its southern tip called Anak Krakatau, or Child of Krakatau. And they'd like to save some more.
For Sumatra is at risk. In the space of just three months at the beginning of 2005, two giant earthquakes rocked the region. A tremor on Dec. 26 produced a tsunami that knocked the earth off its axis and killed nearly a quarter of a million people. Then, on March 28, came another huge earthquake, this time farther south. There was no large tsunami generated by that temblor—dubbed the Nias quake after the island off the Sumatra coast that was worst affected—but over a thousand islanders died. After two such devastating blows, the inhabitants of Sumatra might be forgiven for assuming that nature will leave them in peace. It probably won't. Sieh, 54, and other scientists are warning that the island's troubles are not over. It isn't as though anybody needed a reminder, but the Oct. 8 earthquake that leveled large swathes of Pakistan and Northern India, leaving some 73,000 dead and millions homeless, could be a small taste of what is to come in Sumatra.
Even by Indonesia's chaotic standards, 2005 was a tough year. First came the gargantuan task of cleaning up and rebuilding after the tsunami—a job rendered more challenging by incompetence, bureaucracy and corruption. Then came the sudden eruption of bird flu that constantly threatened to explode into a major epidemic, and fresh bombings in Bali, which sent the country's tourism industry into a tailspin. But such problems would pale in the face of yet another monster earthquake striking Sumatra. That could kill hundreds of thousands of people. Such a quake, moreover, might trigger not just another tsunami but force a volcano to erupt, as happened with Mt. Talang, which was jolted out of an almost 40-year slumber by the Nias temblor.
How sure can we be that another catastrophe is coming? A combination of historical, geographical and geological research accumulated over some 12 years of painstaking field and laboratory work emphatically suggests that a section of the coast several hundred kilometers long, and populated by more than a million inhabitants, is threatened by the possibility of another shock. "There has never been a more certain geological prediction," Sieh declares. "There will be another gigantic earthquake and tsunami south of the equator off the west coast of Sumatra. It could be tomorrow or it could be in two decades from now, but there is no doubt that it will happen and that if the towns and villages along the coast aren't prepared, many, many people will die again."
Read more:
http://www.time.com/time/asia/2005/disaster/story2.html