Wednesday, June 1, 2005

Tonight we’re anchored on the protected side of the small island north of the town called Ujung Salang, on the west coast of Simeulue. Rich, Danny and Nug used the helicopter to hop from reef to reef along the northern coast of the island, measuring uplift, while the rest of us remained behind to cut the coral at Lewak. We’ve rendezvoused here, minus the TV crew, who started motoring back to Sinabang along the east coast early this afternoon. They need to catch their plane out tomorrow morning.

We cut a nice slab of coral this morning at Lewak. Several men helped us lug the equipment the few hundred meters through town to the reef, and to lug it and the sample back to the boat.

Today we realized that all the uplift along the northern coast, between Lewak and Ujung Salang, occurred during the December earthquake. The guys have found no differences between Danny Natawidjaja and my measurements in January and today’s measurements. (Danny is an Indonesian geologist. He and I are the scientific leaders of this effort.) We have now shown that the December and March uplifts overlap only slightly and that there is a clear saddle in the uplift values between the uplift regions of the two giant earthquakes.


Here at Ujung Salang the emerged reef has matured appreciably in the four months since Danny and I visited. Grass has begun to grow on the reef platform and even on the tops of some of the coral microatolls. I wouldn’t be surprised if within 10 years the whole reef is covered in grasses, shrubs, and small trees. It will be interesting to see if the farmers replant coconut groves on the new ground. And there is a new beach forming on the edge of the newly emerged coastline. Photo 8 shows the new beach strand along the new coastline. The old village, which sits in the trees on the left in the photograph, was almost completely destroyed by the December 26th tsunami; a new town is being built against the hill on the right. The lines of trees above the new village are a clove orchard.

The fishing boat that we saw in the trees last January has been carried out onto the reef and is nearly repaired and ready to return to the sea. How they are going to get it over the 1.5-meter-high new beach is a mystery to me. Will they shovel a path through it or just brute-force the ship over it? The captain of the boat came over to ask me for a “souvenir”—that is, a handout. I asked him where he was during the tsunami that carried the boat into the trees. I was amazed to hear him say that he was on the boat and rode out the tsunami on it. He described how the sea first sucked him out as it receded. The sea then came back at him as a 5-meter-high foaming bore, which he headed directly into and managed to ride over it. He and the ship were sucked back out and sent back in again twice. The third wave carried the boat into the woods and left it there. Do I believe this story? Not sure.

Friday, June 3, 2005

Well, last night Aron, Nug, and I were abandoned by the helicopter and thought we would end up spending the night in a small town halfway up the west coast of Simeulue. Machfuld had been shuttling both survey crews southward along the coast in a leapfrog manner all day. By mid-afternoon he needed more fuel, so he headed south to our prearranged anchorage for the night, Busong Bay. Unfortunately, the cargo boat had gotten the wrong information about the rendezvous point and was nowhere to be seen. It didn’t arrive until about 5:30, so the fuel couldn’t be gotten into the helicopter until just before dark. So the helicopter had to stay put for the night.

We had no way of knowing this, of course, so we just passed the time shooting the breeze with a crowd of local guys who had come out to find out what we were doing. When we all had gotten a little hungry, an hour or so before sunset, one of the younger guys fashioned climbing gear out of two pieces of tree bark and climbed one of the coconut palms to retrieve a half dozen coconuts (photo 9). By 6:30 we knew we’d not be getting back to the ships by helicopter and began discussing our options with our new friends. They offered to find another friend who had a car and drive us back the three or so hours to our boat. Or, they would ask the village mayor to house us for the night.

As we sat in a small, two-room home, lit by a lone kerosene lamp, we talked about the earthquakes and tsunami and how it had unsettled their lives. Our expressed opinions that a repetition of the giant earthquakes was not likely for decades or longer here calmed them, and they were thankful for our explanations and opinions. About 7:30 or 8:00 p.m. a young guy came by with a pickup and we began Mr. Toad’s Wild Ride through the countryside. I rode up front with Ikbar, our 20-something driver; Nug and Aron rode in the bed of the truck. Ikbar had been living in the town of Meulaboh at the time of the earthquake and tsunami of December 26th. Of the 100,000 or so inhabitants there, he and his parents were among the 25,000 or so to survive. He said that he and his parents had been taught about the 1907 Simeulue tsunami and knew to run for the hills when the sea withdrew after the earthquake.

Today we were joined by another film crew. These two guys, Edwin and Roeland, are from a production company that is doing a piece for Discovery Channel. In the morning they filmed us cutting two corals from the small island in the middle of the bay and did a little bit of flying around for their benefit. Rich, Danny, and Nug used the helicopter in the morning to finish up our measurements here on Simeulue.

Tonight both boats leave on the long trip back down south to Nias Island, expecting to reach the town of Gunungsitoli tomorrow midday or so. I’ll stay with Machfuld, Edwin, and Roeland at a surfer’s house on shore tonight. We’ll fly down to Nias tomorrow morning and spend the day filming.

Saturday, June 4, 2005

Last night in the field, anchored here in Gunungsitoli harbor again. Aron and Rich, Imam, and Nug will stay on to finish up measurements, especially in the Banyaks, where we have only two measurements to constrain the pattern and magnitude of submergence.

 

 

The highlight for me today was our stop at a small village at the mouth of a small river on the north coast of Nias. Flying over a couple weeks ago, I had seen striking evidence of liquefaction of the delta sediments, so I thought this might be a rather spectacular place to film the effects of a large earthquake. Hundreds of light gray sandblows (features formed by the expulsion of liquefied sand during and after an earthquake) dot the fields just outside the town. These are a common occurrence on the loose, saturated sandy sediments at the mouths of rivers. Residents told us the fountains of water and sand began about halfway through the shaking of the March 28th earthquake and that water continued to flow up to four days afterwards. In the town, which sits on the west side of the river, large fissures opened up and wrecked many of the houses and the mosque (photo 10).

Our last stop of the day was at Onolimbu, a town on the easternmost tip of Nias, and also at the mouth of a river. There was no obvious evidence of liquefaction there, but compaction of the river sediments had caused much of the town to settle down into the intertidal zone. Much of the town is now flooded during higher tides and some homes and former beachfront have actually slumped meters down beneath the sea (photo 11).

For all its problems though, this little corner of the world is still a beautiful place. . . (photo 12).

All images courtesy of Kerry Sieh/Caltech Tectonics Observatory