Belakangan ini ada beberapa hal yang melayang di pikiran terus:
# lagi belajar tentang komponen vertikal, korelasinya dari interplate coupling ke surface deformation. Yang kutau, interseismic biasanya uplift, rupanya adalah long term interseismic. Nyatanya, di area studiku, dapetnya subside, not uplift. Dann,, berdasarkan paper Ito 2000, di northeast Japan juga subside. Hari ini, baca EoS dimana Pak Kato -ERI todai juga mempertanyakan mengapa di northeast Jepang subside? Apakah pertanyaan ini masih on going question??
# Tentang potensi gempa. Gempa-Tsunami itu terasa jauhhh…kalau belum ngalamin sendiri.
Masih inget banget waktu kejadian Aceh 2004 itu, baru aja belajar dan “ngeh” ttg Tsunami, dan kayanya jauh dari kenyataan! ehh,, beberapa waktu kemudian, lagi nonton TV, ada berita gempa di Aceh, berapa jam kemudian, berita tsunami, esoknya, liat video Aceh “rata”, esoknya lagi liat video tsunami dari video amatir…
Waktu 3.11 Tohoku, lagi asik nyimak workshop di Todai, anak-anak asik nonton doraemon di bawah meja, ada goyangan,, kecil awalnya, hingga ke goyangan kapal! bener-bener,, ga akan lupa. beberapa menit kemudian, ada berita potensi tsunami. semalaman gempa ga berhenti, dan TV udah sibuk menyiarkan video tsunami… arus informasi lebih cepat…
Kejadian tohoku aja yang diprediksi ber-M7 dibilang “we completely failed to estimate this”(Hiroshi Sato,ERI Todai,to EoS),
Aceh 2004 bener2 di luar prediksi..
kl intervalnya 500-1000th, gmn meneruskan pesan ke generasi cucu2 tanpa hilang?
“nobody expected a M9 earthquake” ya iya lahhh…
Sekarang ada potensi di Padang, juga di Nankai-Tokai-Tonankai Jepang,, dan baru-baru ini potensi di Selat Sunda mencuat ke permukaan..
..simple way..be prepared, get ready!
we live together with the geodynamic of the earth..
Kadang berpikir perlukah mengeluarkan biaya mahal2 untuk segala peralatan survey??? GPS, dan kawan-kawannya.. kenapa ngga langsung saja praktek lapangan menyusun semua infrastruktur supaya siap, membentuk masyarakat dan generasi penerus yang siap, membangun tugu di lokasi2 genangan tsunami dan tinggi tsunami maksimum..
Tapiii,, aku juga sadar,,, penelitian gempa mendapat kemajuan yang signifikan sejak adanya alat2 survey.. pemahaman cepat meningkat… dan bisa lebih “tepat” memberikan perencanaan…
everyday that I passed here lead me to one important decision: Aku terhempas di sini, so do it well!! as kata suami, papah, sensei dan anak-anak tercinta ^^
Well, for this article, biar ngga kehilangan jejak, aku ketik ulang,dari EoS Vol 92, No 17, 26 April 2011
Concerns Over Modeling and Warning Capabilities in Wake of Tohoku Earthquake and Tsunami
Improved earthquake models, better tsunami modeling and warning capabilities, and a review of nuclear power plant safety are all greatly needed following the 11 March Tohoku earthquake and tsunami, according to scientists at the European Geosciences Union`s (EGU) General Assembly, held 3-8 April in Vienna, Austria. EGU quickly organized a morning session or oral presentations and an afternoon panel discussion less than 1 month after the earthquake and the tsunami and the resulting crisis at Japan`s Fukushima nuclear power plant, which has now been identified as having reached the same level of severity as the 1986 Chernobyl disaster.
Many of the scientists at the EGU sessions expressed concern about the inability to have anticipated the size of the earthquake and the resulting tsunami, which appears likely to have caused most of the fatalities and damage, including damage to the nuclear plant.
“We completely failed to estimate this occuring, the tragic earthquake and tsunami,” Hiroshi Sato, professor at the Earthquake Resarch Institute (ERI), University of Tokyo, told EoS in an interview.
During the 8 April morning EGU session, Sato explained that prior to 11 March, many evaluations had indicated that the maximum magnitude of future earthquakes in the northern Honshu region of Japan would be around 8. “Nobody expected a magnitude 9 earthquake,” he said.
Noting that the northern Honshu region, where the 11 March earthquake struck, forms a classic example of a trench/arc/back-arc system, Sato said that direct measurement of the megathrust activity is needed to better understand seismicity in the region. “To evaluate the risk of subduction megathrust, we have to handle the records covering longer time periods. “What is really needed is “to understand the whole process of starin buildup and release in the subduction zone.”
Sato also noted that the region had experienced four or five large tsunamis over the past 3800 years and that the area submerged on 11 March is similar to the distribution of the tsunami resulting from the great Jogan Earthquake in 869 C.E.
“The earthquake we suffered on March 11 was much bigger than what we expected and have experienced, and that was devastating not just for people but for scientist,” added ERI professor Teruyuki Kato.
Kato said that although Japan already has a vast Global Positioning System (GPS) array and many other instruments, including tidal gauge records and ocean bottom pressure sensors, there is a need for more observations to monitor seismicity and tsunamis. “In the coming days,” Kato said, “we should deploy a dense array offshore in the hypocentral region from the northern end of Japan to the southern end of the Japanese island, not just for Japan but for any subduction zones that could be eligible for megathrust earthquakes.”
He also mentioned some key questions that need to be resolved, including why the northeastern Pacific coast subsided rather than uplifted. “We have to think about what kind of mechanism is working there,” he said.
Emile Okal, professor in Nortwestern University`s Department of Earth and Planetary Sciences, Evanston, III., said the earthquake itself, with its classical subduction quality, was not surprising.However, he said several aspects were surprising, including its size, making the Tohoku-quake the fourth-largest event ever recorded for which a documented, verified seismic moment is available.
Megaquake that reach magnitude 9 “were generally unknown” in old subduction zones, Okal said, adding that megaquakes also were “generally unknown” in relatively poorly sedimented areas. “So several models, several paradigms of the expectability of these mega events, have to be abondoned now,” he explained.
“We thought we were smarter that Mother Nature, and Mother Nature has tought us a lesson. It`s a lesson in humility when you realize that, “gee, I thought I understood something and I don`t,” Okal told EoS.
He added that there has to be a precautionary approach regarding megquakes and that scientists should consider that all long subduction zones of more than 400 or 500 kilometers may produce very large earthquakes in the future. “There are a few places where we felt a little bit too secure, and we have to renewwd and new vigilance,” Okal said, specifically noting Tonga and the Kermadec Islands, the Mariana islands, Java and East Luzon, the Caribbean, and the Solomon Islands.
During the afternoon panel discussion, scientist also focused on the nuclear crisis affecting Japan that resulted from tsunami waves damaging the Fukushima power plant. “What is is order is a review of nuclear plants,” many of which are located along shorelines, Okal said. He recommended that scientists investigate how other such nuclear plants might fare under similar conditions.
Andreas Stohl, senior scientist with the Norwegian Institute for Air Research, Kjeller, Norway, who has developed an atmospheric dispersion model useful for tracking various materials including radiation released at the Fukushima power plant as well as volcanic ash that drfited across Europe last year from Iceland’s Eyjafjallajokull volcano, said the risk of nuclear power should not be judged by the accident at the Fukushima power plant, because the evnt could have been even worse.
“We were extremely lucky that the wind was blowing tn the right way, ” out to the sea, he said. “imagine the same situation in a nuclear power plant somewhere in central Europe where, regardless of which direction the wind would blow, it`s just a question of which city you pollute most. The risks there will be much higher.”
Stohl said that Europe may need an emergency response center to deal with these types of situations, and he also stressed the need for improved prediction models. “That concerns probably ocean models, but that also concerns especially atmospheric models because that is the immediate threat to people,”Stohl said. ” But there is little opportunity to test these models because, fortunately, these accidents are not happening too often.”
-Randy Showstack, Staff Writers