The crater of Merapi mountain , Jogja , indonesia , expand after eruption
source by indonesia language , link :
TRIBUNnews.com - Tue, November 26, 2013
Tribune Reporter reports Jogja, Ekasanti Anugraheni
TRIBUNNEWS.COM, YOGYAKARTA - The peak of Mount Merapi, experienced a number of physical changes after eruption, Monday (18/11/2013) last week.
It is based on direct observation team and Technological Development Research Center of Disaster geology (BPPTKG) Yogyakarta, while climbing the peak of Merapi on Thursday (11/22/2013) ago.
Direct observation results showed the presence of cracks along the 230-meter leads northwest to the southeast, following the opening of the crater Gendol direction. The fracture shape, tapered at the ends and wide in the middle, to a maximum of 50 meters.
According to the Head of Yogyakarta BPPTKG , Subandriyo, it is the largest fracture after eruption 2010. Previously, cracks are also much smaller form, but BPPTKH not count them one by one.
In addition to fractures, in the southwest side of the crater also experiencing widening hole up to two times larger as a result of the eruption were as high as 2,000 meters yesterday. In the photos presented BPPTKG, indicated crater section bring many of white smoke.
"Previously, the hole only about 30 meters , but now widened," said Section Head BPTTKG Merapi Yogyakarta Sri Sumarti who participated in the expedition along with nine others on Monday (25/11/2013).
Upon a change in peak condition, Subandriyo suggested that hikers stop in his journey to Bubrah market / Pasar Bubrah . to anticipate the unexpected activity of Merapi.
In addition to direct observation of Merapi peak condition, the team also took the material sample eruption on Monday (18/11/2013). The study of the samples showed no evidence of new material from the merapi stomach when carried being eruption.
it can be concluded that the eruption was a phreatic eruption that character for a moment as predicted Subandriyo some time ago.
It was automatically dismissed statements Former Head of Volcanology and Geological Hazard Mitigation (PVMBG) Surono which states that it is most likely magmatis eruption.
according index Volcano eksplosivity, Merapi eruption yesterday scale is small which is one of the eight level scale. It was based on the amount of material that was brought Merapi which is only about one million cubic meters of material.
Original text :
Kawah
di Puncak Merapi Semakin Membesar Pascameletus
TRIBUNnews.com – Sel, 26 Nov 2013
Laporan Reporter Tribun Jogja Ekasanti Anugraheni
Itu berdasarkan pantauan langsung tim Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan geologi (BPPTKG) Yogyakarta, saat mendaki puncak Merapi pada Kamis (22/11/2013) lalu.
Hasil pantauan langsung menunjukkan, adanya rekahan sepanjang 230 meter mengarah ke tenggara barat laut, mengikuti bukaan kawah dari arah Gendol. Bentuk rekahan itu, menyempit pada ujung-ujungnya kemudian melebar di bagian tengahnya hingga maksimal 50 meter.
Menurut Kepala BPPTKG Yogyakarta Subandriyo, rekahan itu merupakan yang terbesar pascaerupsi 2010. Sebelumnya, rekahan-rekahan yang lebih kecil juga banyak terbentuk, tapi BPPTKH tidak menghitungnya satu persatu.
Selain rekahan, dalam kawah sisi barat daya juga mengalami pelebaran lubang hingga dua kali lipat lebih besar akibat letusan yang setinggi 2.000 meter kemarin. Dalam foto yang dipresentasikan BPPTKG, ditunjukkan bagian kawah itu banyak memunculkan asap berwarna putih.
"Dulunya hanya sekitar 30 meter lubangnya, tapi sekarang melebar," ucap Kepala Seksi Merapi BPTTKG Yogyakarta Sri Sumarti yang turut serta dalam ekspedisi beserta sembilan orang lainnya, Senin (25/11/2013).
Atas perubahan kondisi puncak itu, Subandriyo menyarankan agar para pendaki menghentikan perjalanannya hingga di Pasar Bubrah saja. Hal itu, untuk mengantisipasi adanya aktivitas Merapi yang tidak terduga.
Selain pantauan langsung kondisi puncak Merapi, tim juga mengambil sampael material hasil letusan Senin (18/11/2013). Hasil penelitian terhadap sampel itu menunjukkan, tidak ditemukan adanya material baru dari perut Merapi yang terbawa saat letusan.
Tidak ditemukan material mineral misalnya belerang di puncak Merapi. Kalau memang benar ada sample material itu berasal dari perut Merapi, harusnya ada kandungan mineralnya
Dengan demikian, bisa disimpulkan bahwa letusan itu merupakan letusan freatik yang sifatnya sesaat sesuai prediksi Subandriyo beberapa waktu lalu.
Hal itu otomatis menampik pernyataan Mantan Kepala Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) Surono yang menyatakan bahwa kemungkinan besar letusan itu ialah letusan magmatis.
"Hanya ada material lama hasil hancuran kubah kava 2010. Hasil penelitian menunjukkan ini adalah murni letusan freatik. Tepat sesuai prediksi kami," tegas Subandriyo dijumpai di kantornya.
Sesuai Volcano Eksplosivity Indeks, skala letusan Merapi kemarin terhitung kecil yakni skala satu dari delapan tingkatan. Hal itu berdasarkan jumlah material yang dilontarkan Merapi yakni hanya sekitar satu juta meter kubik material.
Sebagai perbandingan, skala Erupsi Merapi 2010 mencapai skala empat dengan total material yang dilontarkan sebanyak 100 juta meter kubik. "Status Merapi masih normal," tegasnya.
