Mount Merapi

Here is my Merapi case study, void of any photos at the moment because I think I might fall asleep but I'll put some photos up soonish (if I remember...) 

·             Active Stratovolcano (composite)

·             Located on the border between central Java and Yogyakarta

·             Has erupted regularly since 1548

·             Thousands of people live on the flanks – high risk from mass movement e.g. Lahars

·             2010 was the largest eruption since the 1870s

Background to the Volcano

·             Found where the Indo-Australian plate is subducting beneath the Eurasian plate.

·             Used to be basic; basaltic lava, effusive but now it’s more intermediate; antedesitic lava and explosive which cause lava domes that produce pyroclastic flows when they collapse

Chronology of Events

·             25th October – Three major eruptions are recorded

·             26th October – A column of smoke rises 1.5km from the top of the volcano, also the first fatalities are recorded

·             29th October – Pyroclastic flowing 3km down the side of the volcano for 4-9 minutes, pyroclastic flows also hit the Lamat, Senowo and Krasak rivers. Pollution of water courses – social + environmental

·             30th October – Eruptions get more violent, ash fallout is found over 30km away and police/military personnel posted closest to the volcano are seen fleeing with civilians, which cause a mass ‘clog’ of the roads. Heat clouds flow into the Krasak and Boyong Rivers (heat pollution, not good). Yogyakarta’s airport was closed from 05:00 until 07:00. A pyroclastic flow headed toward Gendol River, Kuning River, Krasak River, and Boyong River. A fresh eruption then caused sand to rain up to 10km away

·             1st November – Louder explosions than before caused a sudden rush of panic evacuation clogging the transport systems. A continuous stream of steam clouds was sent into the air for 40 minutes. The ash from that day reportedly raised 1.5km into the air; air travel is disrupted. Over 70,000 people have now been displaced and some are beginning to develop health issues such as respiratory infections and eye irritation.

·             2nd November – 26 Pyroclastic flows are reported

·             3rd November – Heat clouds travel up to 10km from the volcano, forcing the government to evacuate previously set up refugee camps. 38 pyroclastic flows reported in the first 12 hours of the day, 19 of which travelled 4km south. Volcano spewed ash and cloud 5km into the atmosphere for an hour. Biggest eruption so far, 3 times that of the eruption the week before

·             4th November – Heavy rain the night before triggered Lahars with mixtures of water and rock debris cascading down the Kuning, Gendol, Woro, Boyong, Krasak and Opak rivers on the slopes of the volcano, a bridge was destroyed. The volcano had now been erupting for 24 hours with the largest eruption being recorded at 05:55. Heat clouds of between 600° and 800° spread 11.5km and reaching toward the edge of the 15km exclusion zone.

·             5th November – Another major eruption causing the extension of the exclusion zone to 20km, residents within 15km asked to leave for safety. Bronggang, 15km from the volcano had its’ streets covered with 30cm of ash. 100,000 people had now been evacuated and the scientists began to retreat.

·             6th November – Just before midnight smoke, hot air and jets of flames as high as 3km occurred in the north, west and east. The official exclusion zone remained at 20km after a day of high activity.

·             7th November – Merapi continues to ‘belch’ out pyroclastic flows with hot ash heading towards the Gendol and Woro rivers. The death toll on the slopes now reached 135. Police report that they’re having difficulty keeping people out of the exclusion zone.

·             8th November – Gas and ash soared 4km into the air

·             9th November – Bodies were retrieved from villages, which had been destroyed by pyroclastic flows as the volcano intensity dies down. Hot ash is confirmed to be reaching heights of 14.5km making it the biggest eruption in Merapi’s history. A 5.6 magnitude earthquake was measured in Yogyakarta yet it had no connection to the volcano.

·             11th November – The volcano continued to erupt however at a reduced intensity. 17 avalanches, 1 hot ash eruption and 1 volcanic earthquake were reported.

·             17th November – Hot air clouds, smoke columns, avalanches and volcanic eruptions continued on the 16th, 17th and 18th. The main threat was from hot air and ash clouds whilst lava injections were regarded as an indirect threat.

·             Late November – Merapi was still a threat due to hot ash clouds however eruptions (although still frequent) were decreasing in intensity. Lava and lahars are regarded as indirect threats. The exclusion zone is between 5 and 20km

·             December – The official volcano threat level is reduced from 4 to 3; the threat level had been increased to 4 in late October. Although the threat level had been reduced volcanologists maintained that there would be threat from hot ash and possible lahars. An ongoing exclusion zone of 2.5km was set up.

Management

·             The government initially set up refugee camps within 15km of the volcano yet these needed to be moved further as the volcanoes intensity increased.

o    This resulted in logistical problems with the movement of people resulting in poorer healthcare being provided

·             On the 7th November the price of vegetables was reported to be increasing, many schools also began to close.

·             The Health Ministry reported on the 7th November that the supplies to deal with the many refugees were not sufficient but they could manage.

·             9th November, the Chairman for the Indonesian Red Cross calls for education and training to be provided to help deal with Natural Disasters in the future.

·             11th November, a report suggests that the refugees will start developing mental health issues due to the events and the limbo between refugee camps. 1 man has already committed suicide due to stress.

Casualties and Displacement

353 people died overall. Most of the casualties were a result of gas clouds, respiratory problems and burns. Some deaths were also caused by road accidents as evacuation took place. On the 11^th November it was reported that the volcano had displaced 350,000 people. 800 people are reported to have suffered minor to severe physcological trauma due to the volcanic events.

Stuff to link to SPEED:

Social – loss of life/buildings, mental health issues

Political – Had to call on help from UAE

Environmental – Huge amounts of pollution to river systems, thermal pollution and nasty gases

Economic – Increases in food prices whilst people aren’t getting a wage

Demographic – Reduction in workforce through death/illness means a reduction in the economy and the ability to produce what’s needed for the country e.g. food.