Feeds:
Posts
Comments

Posts Tagged ‘subduction zone’

Bali Day 2: Sunday, August 6, 2017

Batur caldera panorama-s

A panoramic view of the Mt. Batur caldera as seen from my restaurant in Kintamani. The darker areas of the cone are lava flows from the 2006 eruption.

We left the coffee plantation and continued our journey up the side of Mount Batur. At higher elevations, there were orange groves and stands selling oranges, small towns in valleys as we ascending the ridge lines, and ever more clouds. I tried taking photos of the oranges but the car was moving too fast to get a clear shot. Up ahead the clouds seemed to engulf the roadway, but as we reached it I saw that we had crested the edge of the caldera. We had arrived at the heart of Gunung Batur, which is the beating heart of Bali itself.

Batur details

A close-up view of Mt. Batur on Bali. You can see smoke rising from fumeroles about 1/3 of the way down from the top; this is the active site of the 2006 eruptions, marked by the black lava flows that are only just beginning to be colonized by plants.

I had been afraid that I would face the same problem as at Mount Merapi three days before, especially since it had rained this morning, but luck was with me this time. The clouds were higher up than the central mountain and there were patches of sunlight shining on the peak. We drove a short distance along the edge of the crater and stopped at a white restaurant in Kintamani that hung out over the edge. Gusti said this would be where I would eat lunch. It was an Indonesian buffet. I felt guilty being the only one of us eating; Gusti and the driver were staying with the car, waiting for me to get done. I’m not used to being an exclusive guest, but I did pay 50% more for this tour because I was by myself.

Reataurant at Batur

The restaurant in Kintamani where I ate lunch, hanging over the caldera’s edge. You can see the ridges in the background right that are formed by the double ring of the caldera.

I was assigned a seat overlooking the caldera and parked my camera bag while I got lunch. The buffet dishes were pretty good, but the vegan soup was the best. There were banana fritters, fried rice and fried noodles, chicken satay (on a skewer), and other dishes. I sat my food down and took photos of it with the mountain in the background. Before eating, I took advantage of the sunlight and took a series of photos of the entire caldera in a panoramic view as well as close-ups of the mountain itself. Misty clouds kept trying to blow in, and I could tell the mountain would be covered later on, but for now the view was excellent.

Gonna plug that mountain

Something tells me my finger won’t be enough to plug this mountain if it decides to blow . . .

Gunung Batur is an active volcano, a composite peak growing inside a double-walled caldera. Gusti had told me that it last erupted in 2006, only 11 years ago. I could see smoke rising from fumeroles on an area about 1/3 down from the top of the peak directly in front of my position, with fresh lava flows spreading from that position down into the bottom of the caldera. The town of Kintamani was threatened and eventually moved (mostly) up to the top of the caldera rim.

3D model of Batur

A 3D model of Mt. Batur on Bali. My restaurant was at the 7:00 position on the south rim of the caldera. You can see that it is a double ring – this mountain has blown up and collapsed at least twice, then the composite cone has formed again. The flat area to the right is the surface of the lake. This data comes from the USGS Earth Explorer website and is modeled in Daz3D Bryce.

It was hard to tell from this side, but my 3D models of the mountain show a definite double wall with the central peak growing inside both rims. The eruptions that made these walls were violent indeed, blowing the top off the mountain many years ago and collapsing the magma chamber to form the caldera that I was eating on top of. To my left I could see the double ridge of the rims. To my right was a large ridge and beyond that, a beautiful blue lake, the largest on Bali. The far wall of the caldera rose beyond the lake. Various ages of lava flows could be determined by their degree of coverage in brilliant green foliage; the 11-year-old flows were just beginning to succumb to the plants’ encroachment.

Gusti with Gunung Batur

My tour guide, Gusti, at the rim of the Mt. Batur caldera. He is an excellent guide, with a great amount of knowledge about all things Bali as well as good English skills. I highly recommend looking him up for tours of Bali.

This was an incredible sight and my first good look at an Andesitic or composite volcano up close. When I took my two oldest children to Washington in 2000, we visited Mt. St. Helens but the mountain was shrouded in clouds, just at Merapi had been. I had been 0 for 2 until today. But now I’m 1 for 3, and the wait was worth it. This will be very useful for my earth science classes this year, as well as my fly-overs of Mt. Bromo and the other volcanoes.

Active volcanoes in Indonesia

A USGS map of active volcanoes in Indonesia. Bali has both Mt. Batur and Mt. Agung, with Mt. Rinjani on a the nearby island of Lombok. There are 125 active volcanoes in Indonesia, the most of any country. They from a series of arcs where ocean crustal plates are colliding.

The Indonesian island arc of Sumatra, Java, Bali, and so on to the east sits at the edge of a very active subduction zone, where the Philippines Plate is being pushed into the Indian Plate. The Indian Plate is being pushed below, and materials eroded off the islands are caught in the subduction zone, along with water. These light materials are heated and rise to the surface as large plutons of magma, high in volatiles, that explode when they reach the surface. Repeated pyroclastic ash and andesite eruptions create the composite cones. When a magma chamber explodes and then collapses, a caldera forms. Here at Mt. Batur, one can see both, a testament to the long-term violence of Earth’s tectonic plates.

Lake Batur panorama-s

A panoramic view of Lake Batur, the crater lake inside the caldera. We drove east along the caldera’s edge until we found this overlook.

After lunch we took some photos at the wall in the parking lot, then I convinced Gusti to drive me around the rim further to get a better look at the lake and to see the mountain from a different angle. The view kept shifting as we traveled, and we found roads to take us even though we left the main highway. Gusti seemed to know every road on Bali. We stopped eventually at a pull out with a great view over the lake and back to the mountain. I took further photos, which I have pieced together into the panorama you see here. I was reluctant to leave such a view, but our next stop awaited us.

Batur from other angle 2

Gunung Batur seen from a different angle as we traversed the caldera’s rim.

Lunch with Mt. Batur

My lunch overlooking an active volcano. Some people take early morning hiking tours of the mountain and each a lunch of eggs roasted in the fumeroles of Mt. Batur.

Appease the mountain god

A local shrine to appease the mountain gods.

David by Lake Batur

David Black overlooking Lake Batur with the composite volcano cone in the distance.

Advertisements

Read Full Post »

Yogyakarta Day 2: Thursday, August 3, 2017

David with jeep on Merapi

David Black on a jeep tour of Mt. Merapi near Yogyakarta, Indonesia.

After visiting Mendut Temple I was famished, so we stopped at a restaurant that had its own shrimp ponds and I ordered some honey roasted shrimp on skewers with the usual rice. It was a bit more expensive than other meals I’ve had in Indonesia, at about $15 US, but was delicious. I shouldn’t have had the smoothie to go with it, as it put me over the top on how much money I had left to spend.

Honey grilled shrimp

Honey glazed shrimp, one of the more delicious dishes I ate in Indonesia.

We traveled on toward Gunung Merapi, one of the most active and dangerous mountains in Indonesia. We gradually climbed up the mountain slope, passing through towns and smaller villages. It had been clear earlier, but clouds were beginning to gather again as the day wore on and sea breezes blew in moisture which rose up over the mountain and formed clouds. I dozed off a bit, but the rough road made sleeping difficult.

Charred furniture

Charred furniture, burnt by the pyroclastic flows of Mt. Merapi in the 2010 eruption.

After about 40 minutes of driving, we reached a series of dirt parking lots with jeeps pulling in and out. We parked and my driver took the rest of my money to pay for the ticket. I didn’t have any left for a tip for my jeep driver.

Charred motorcycles

Ruined and charred motorcycles, found under the volcanic ash after the eruption of Mt. Merapi in 2010.

I was the only one in my jeep. There is something to be said for traveling with other people, as this traveling alone can get tiresome. I wanted to share these experiences with others in the moment, not just later through these blog posts. I climbed into the back and we drove off, leaving the oiled road onto smaller trails that were barely trails at all. I tried to take some video but was knocked around so much it was impossible, so I simply tried to take photos.

Ruined bike in window

There’s not much left of this bicycle, or this house, after Gunung Merapi erupted. Artifacts from around the village have been collected for display here, a kind of impromptu museum to the eruption, which was only seven years ago.

We were heading through the jungle to a village that had been destroyed by the last eruption of Mt. Merapi in 2010. Over 350,000 people were evacuated, but the ash and fumes caused many problems with the local population and rescue workers alike. Some people either refused to leave or snuck back in before the alert was lifted, and 353 people died. The eruptions began with seismic activity in September, then pyroclastic flows and major eruptions from October to the end of November, 2010. By the start of December, the mountain quieted down again and people were allowed back to what was left of their homes.

Artifacts in ruined house

Pots, pans, and cooking stove destroyed by the 2010 eruption of Mt. Merapi in Indonesia. It felt like visiting Pompeii, but these items are only seven years old, a testament to the powerful forces that continue to shape our planet. Merapi is even more dangerous that Vesuvius in Italy.

We parked in a small lot and entered what had been a home. Artifacts of burnt out furniture, motorcycles and bicycles, and other everyday items were on display inside the charred remains of the house. It was a sobering reminder of the power of this mountain. Now it is a tourist destination.

Ruined motorcycle

Another melted and ruined motorcycle, on display at village that was destroyed by the 2010 eruption of Mt. Merapi in Indonesia.

We drove on along roads barely laid out in the volcanic ash of the eruption and parked next to a large boulder. This rock is the size of a minivan or small truck and was ejected from the volcano, traveling miles through the air to land here. I posed by it, of course. We could also look out over the lava flow itself, which issued through a small cleft in the lower reaches of the mountain.

Ruined road

Roads in the area were destroyed by the pyroclastic flows, and are now only barely passable by jeeps and motorcycles. I finally figured out to just let my body go with the bouncing, rather than trying to fight it.

Unfortunately, the mountain itself was shrouded in clouds, just as Mt. St. Helens had been when I visited there with my two oldest children in 2000. I am 0 for 2 with viewing active composite volcanoes. I’ll have one more chance with Mt. Batur in Bali.

David by alien rock

This rock was blasted out of the volcano and landed here, several miles away. From this location, one can see the main pyroclastic flow and how it is now being mined and used for concrete.

We drove higher up the mountain on a road that had been wrecked by the eruption and now was one of the roughest roads I’ve ever been on. Some sections still had asphalt on them, others were eroded and ruined, cut down to the underlying dirt and filled with huge potholes. A group of motorcyclists were having a rough go of it behind us, and I was thrown from side to side. I finally figured out it was better just to let my body go with the flow instead of trying to resist the violent motion. My hat is off to my driver for his skillful handling of the jeep.

Lava cleft

The main flow erupted through this cleft in the side of Mt. Merapi, then spread out to clog river channels and obliterate entire villages. Unfortunately, because I spent a bit too much time at Mendut Temple, the clouds had collected around Mt. Merapi itself and I wasn’t able to see it (except from the air the day before).

We came up to the end of the road at a parking lot next to the main pyroclastic flow from the eruption. Two people sought shelter in a bunker at this location as the flow came down the mountain at nearly the speed of sound. But their choice of refuge was ill advised, as the flow traveled over the top, burying the bunker underneath. They died inside. It was a bit strange that this has also been turned into a tourist destination. I took some photos of what I could see of the mountain (not much beyond the first ridge line) and the driver took photos of me by the jeep.

Plants on lava flow

The main pyroclastic flow, now turned to volcanic ash. It is already being reclaimed by plants. The main flanks of Mt. Merapi lie in the mist beyond.

Then I loaded back aboard and we traveled a short way down, then out onto the flow itself for some very dramatic photos. Then we returned to our original parking lot.

Lava flow

Another view of the lava flow from further down. We pulled the jeep over to get a better view. If the clouds hadn’t come in, the view of the mountain from here would be spectacular. Maybe some other time. This is the second andesitic volcano I’ve visited and I’m 0 for 2. The other was Mt. St. Helens.

Even though the mountain was obscured, I still enjoyed this excursion and learning about the power of this mountain and the destruction it caused only seven years ago. The area is still trying to recover, and these tourist jeep rides are helping the economy here to come back after the devastation. Already green plants are colonizing the lava flow, and soon all evidence will be erased by the jungle. That is, until next time. I don’t know if I would want to live with such a dangerous neighbor in my back yard.

Rice paddies

Rice paddies on our way down Mt. Merapi. If this mountain is so dangerous, then why do people live so close to it (even on it)? Because the volcanic ash creates very rich soil for farming, and the eruptions are infrequent enough that most people can live an entire life without experiencing one. Humans don’t have very good institutional memory.

I got back into my car and my tour guide drove me back down the mountain on the main road, a welcome relief to my jostled spine. We passed rice fields and groves growing in profusion in the rich volcanic soil. Our ride back to Yogyakarta was about 30 minutes, and he dropped me off at the hotel. It was about 4:00 and I could have gone out to explore some more, but I was very tired from such an early start, so I relaxed in my room, uploaded photos, took a nap, and watched some of the third Terminator movie and the end of Mystery Men. It had been a long but incredible day.

Rice field

Maturing rice fields and coconut palms. The soils on the slopes of this mountain are very fertile, so people continue to live here despite the danger.

Read Full Post »