Ceramah ini membahas aktivitas gunung berapi di Indonesia khususnya Gunung Merapi. Gunung Merapi adalah gunung berapi aktif teraktif dan termuda di Indonesia. Ceramah ini menjelaskan geologi, sejarah letusan, bahaya, dan konflik antara manusia dengan aktivitas gunung berapi Merapi. Risiko utama meliputi aliran lava, erupsi dome, hujan abu, bahaya piroklastik, gas beracun, lahar dan tsunami. Lebih dari 300,000 orang
1. CERAMAH TEKNIK GEOLOGI BIL 14 12 Januari 2011 PEMBENTANG 1: PROF. MADYA DR WAN ZUHAIRI WAN YAACOB AKTIVITI VOLKANIK INDONESIA: GUNUNG MERAPI PEMBENTANG 2: PROF. DR. HAMZAH MOHAMED MINERALOGI DAN GEOKIMIA ABU LETUSAN GUNUNG MERAPI 2010 12/1/2011 1 Ceramah Teknik Geologi 2011
2. Al Quran danGunungBerapi An-Naml ( 27:88) ( the dynamic of earth)"Dan kamulihatgunung-gunungitu, kamusangkadiatetapditempatnya, padahaliaberjalansebagaijalannyaawan. (Begitulah) perbuatan Allah yang membuatdengankokohtiap-tiapsesuatu; sesungguhnya Allah MahaMengetahuiapa yang kamukerjakan". SurahHud: ayat 82. “Makaapabiladatang (masaperlaksanaan) perintahKami, KamijadikannegerikaumLutituditerbalikkan (tertimbussegala yang adadimukabuminya) dankamimenghujaninyadenganbatu-batudaritanah yang dibakar, menimpanyabertalu-talu” 12/1/2011 2 Ceramah Teknik Geologi 2011
3. ` Ceramah Teknik Geologi 2011 12/1/2011 Major Volcanoes of Indonesia 35 45 130 active volcanoes, more than any other country on earth 3
4. TEKTONIK INDONESIA Zonsubduksi: Indo-Australian vs Eurasian plate Gunung “Barisan” B B A A 12/1/2011 4 Ceramah Teknik Geologi 2011
5. GunungMerapi Merapi – “GunungApi” Elevation = 2968 m (3 KM) The most active & youngest volcano in Indonesia (Stratovolcano) Mengeluarkanasap – 300 haridalamsetahun UsiaMerapi: 8.300 and 125.000 years old (Camus et al, 2000) 7000 years (Newhall et al ,1995) 40.000 years (Charbonnier & Gertisser, 2008) 12/1/2011 5 Ceramah Teknik Geologi 2011 A Decade Volcano
15. Ceramah Teknik Geologi 2011 BAHAYA DARI GUNUNG BERAPI Lava flows (aliran lava) Dome eruptions(letusan dome) – Ash fall PYROCLASTIC HAZARDS Poisonous gases (gas beracun) Volcanic mudflows (Lahars) Tsunamis 12/1/2011 11
16. PYROCLASTIC FLOW (WedhusGembel/ nueeardentes/ the glowing cloud / awanpanas / ignimbrite) V = 150 km/j T= 500-600oC Jarak = 7-13 km Mount Merapi releases a pyroclastic flow as it erupts 12/1/2011 12 Ceramah Teknik Geologi 2011
19. 12/1/2011 Ceramah Teknik Geologi 2011 15 SesungguhnyaKamimenimpakanatasmerekasatusuara yang kerasmengguntur, makajadilahmerekasepertirumput-rumputkering(yang dikumpulkanoleh) yang punyakandangbinatang.QS. al-Qamar (54) : 31 IKTIBAR… “Adakahorang yang mahumengambilpelajaran?” – 6 kali ulangandalamsurah Al Qamar “Makabetapadasyatnya AZAB kudan PERINGATAN ku” – 5 kali ulangandalamsurah Al Qamar
Negarayg paling panas, paling garang….sbbbanyakgunungberapidikawasaniniBola sepaksuzuki cup – Malaysia vs Indonesia – pergike Stadium naikkereta ‘PERISAI”
Map of the Indonesian subduction system shows general tectonic setting and distribution of active volcanoes (marked as circles). Arrows indicate the direction of movement (after Gertisser and Keller, 2003)The subduction zone southwest of Sumatra is part of a long convergent belt that extends from the Himalayan front southward through Myanmar, continues south past the Andaman and Nicobar Islands and Sumatra, south of Java and the Sunda Islands (Sumba,Timor), and then wraps around to the north. This trench accommodates the northward motion of the Australian plate into Eurasia. (The trench is known by several local names but here called the Sundasubduction zone in general and sometimes the Sumatran subduction zone when referring to the stretch offshore Sumatra.)
Merapi forms a bell-shaped topography that has a mean dip angle of 5° up to 1300 m and 15° up to the summit of 2911 m (Berthommier, 1990). The porphyric nature of the lava and alternating deposits of lahars and pyroclastic flows forms an un-compacted and highly porous material that is easily eroded. Merapi's morphology is characterized by steep erosional valleys of all sizes and radial ridges (Mizutani, 1990).There are two high temperature fumarolic fields near the Merapi summit, Gendol and Woro, located 150 m and 250 m SE of the centre of the summit crater. The maximum fumarolic temperatures in the Gendol field are greater than 800°C, while those in Woro are higher than 600°C (Zimmer and Erzinger, 2003). The SO2 gas is continuously discharging from the fumaroles and the lava dome.(IAVCEI) – International Association of Vulconology and Chemistry of the Earth’s Interior !. the most hazardous volcanoes on the planet - at least in terms of hazards to people and property.
Violent Eruptions atMerapivolcanoThere are two high temperature fumarolic fields near the Merapi summit, Gendol and Woro, located 150 m and 250 m SE of the centre of the summit crater. The maximum fumarolic temperatures in the Gendol field are greater than 800°C, while those in Woro are higher than 600°C (Zimmer and Erzinger, 2003). The SO2 gas is continuously discharging from the fumaroles and the lava dome.
KeindahanMerapi: Pertanian, kawasanpenempatan (kampung), Pelancongan, terkenaldengankemanisanSalakPondohygditanamdilerenggunungberapiThere are more than one million inhabitants endangered by Merapi. At least 80,000 and perhaps as many as 100,000 people live inside the so-called Forbidden Zone defined by Pardyanto et al (1978).…Snake skin fruit.
The primary danger during the eruption at Merapi Volcano has been pyroclastic flows. These avalanches of hot volcanic gases, ash, and rocks descend rapidly and violently, occasionally at speeds over 150 kilometers (90 miles) per hour. Pyroclastic flows are usually channeled by the terrain, but large and violent flows can spread over a wide area.
Many did but some listened to an 83-year-old man named Maridjan - the spiritual "Keeper of Merapi." PEMEGANG ANAK KUNCI MERAPI For the past 30+ years, WAK Maridjan appeased the volcano by tossing offerings of chickens, rice, and flowers into the crater. I guess the spirit of Merapi was sick of chicken & rice for dinner since Maridjan and a number of his followers died for this foolishness. GambarseterusnyaialahsekumpulanpendudukJawamembawa ‘GunungMerapi’ buatanygdiusungdandiletakkandenganwangpalsudandikelilingimakanansepertijagungdankubis, dipercayaimerekanakmemberimakankepadarohgunungMerapisupayaletupanGunungMerapiygaktiftureda, makanantuakandihanyutkankesungai. Tu le antarakepercayaanmistikbagipendudukJawa.