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Kesan pertama Windows 8 adalah proses instalasi yang cepat. Seperti halnya Windows 7, proses instalasi Windows 8 lebih cepat daripada Windows XP. Windows 8 juga cukup stabil. Pengetesan selama beberapa jam terhadap Windows 8 menunjukkan tidak adanya kendala yang berarti, tidak pernah crash dan tidak lag. Prosesor Pentium 4 2.8GHz dengan RAM 2 GB dapat dengan mulus menjalankan Windows 8 ini. Yang paling menarik dan menjadi nilai jual bagi Windows 8 ini mungkin adalah tampilannya mirip dengan home screen Windows Phone 7. Kotak warna-warni yang berisi shortcut ke aplikasi yang terinstal, game, social network dan sebagainya. Untuk mengakses salah satu aplikasi, cukup klik 1 kali pada shortcut tersebut. Terkesan lebih simple karena pada sistem operasi pada umumnya Anda harus melakukan double click untuk membuka aplikasi dari icon di desktop. Ketika aplikasi terbuka, jangan heran jika tampil di layar penuh tanpa adanya titlebar, window frame maupun taskbar. Tampilan layar penuh ini hanya ada pada aplikasi bawaan Windows 8, namun tidak pada aplikasi yang diinstal sendiri, misalnya Mozilla Firefox. Semoga saja pada masa yang akan datang, aplikasi-aplikasi tersebut juga akan mengadaptasi fitur layar penuh ini. Untuk kembali ke home screen, tekan tombol Windows di keyboard, tekan sekali lagi untuk kembali lagi ke aplikasi. Home screen Windows 8 ini menarik karena berbeda sekali dari kesan tampilan Desktop pada Windows sebelumnya, bahkan jika dibandingkan dengan sistem operasi lain, benar-benar berbeda. Tampilan layar penuh tanpa adanya taskbar dan start menu. Sebenarnya start menu bukan dihilangkan, tapi tersembunyi. Terbukti ketika saya mengarahkan mouse ke sudut kiri bawah muncullah start menu tersebut, dan secara bersamaan di sudut kanan juga muncul tampilan jam dan tanggal dalam ukuran besar. Fitur ini drag and slide juga tidak kalah menarik. Fitur di Windows 8 yang digunakan untuk pindah antar aplikasi yang dibuka dengan cara menarik layar ke kanan. Caranya arahkan cursor ke kiri layar kemudian tekan (klik, tahan) sampai muncul preview jendela aplikasi kemudian tarik ke tengah, maka jendela aplikasi akan terganti disertai efek animasi yang menarik. Windows 8 menawarkan kompatibilitas dengan program-program lama. Sebagian besar aplikasi yang dapat dijalankan di Windows 7 akan berjalan dengan baik di Windows 8. Tampilan home screen tidak serta merta menggantikan desktop seperti pada Windows versi sebelumnya dengan Wallpaper dan icon-iconnya. Desktop masih bisa dengan cara menekan tombol Window + D di keyboard. Shortcut akses ke desktop juga tersedia di home screen.

Fenomena Supermoon akan terjadi lagi pada Minggu (6/5/2012). Sebelumnya, Supermoon terjadi pada 19 Maret 2011. Mutoha Arkanuddin dari Jogja Astro Club (JAC) mengatakan, "Kalau Supermoon tahun lalu terbaik di Amerika, maka Supermoon tahun ini adalah Supermoon terbaik bagi Indonesia." Pada saat Supermoon terjadi nanti, Bulan akan berada pada jarak sekitar 357.000 kilometer, 10 persen lebih dekat dari jarak biasanya. Jarak yang lebih dekat membuat Bulan akan tampak 14 persen lebih besar dan 30 persen lebih terang dari biasanya. Menurut Mutoha, Supermoon tahun ini bisa dinilai yang terbaik dari selisih antara saat terjadinya purnama, perigee, dan saat Supermoon tampak. "Tahun ini purnama terjadi pada pukul 10.30, sementara perigee-nya pada 3.30 UT atau 10.30 WIB. Jadi bersamaan," ungkap Mutoha saat dihubungi Kompas.com, Rabu (2/5/2012). Selisih antara saat terjadinya purnama dan perigee dengan waktu yang memungkinkan untuk pengamatan di Indonesia juga lebih singkat. "Di Indonesia, kita hanya perlu menunggu sekitar 6 jam untuk melihat Supermoon. Kalau di Amerika tahun ini harus menunggu 12 jam," papar Mutoha. Meski istimewa, penampakan Supermoon tak akan bisa disadari dengan mudah. Diperlukan teleskop untuk membandingkan besarnya bulan saat Supermoon dengan saat purnama biasa. Mutoha dan anggota komunitas JAC berencana membuat dokumentasi agar publik menyadari perbedaan besar Bulan tersebut. Sementara itu, Mutoha menegaskan bahwa tak ada kaitan antara Supermoon dengan bencana dan gempa bumi. Meski demikian, dampak Supermoon pada air pasang perlu diwaspadai. Sumber : sains.kompas.com

A research of tsunami generated by the October 25th 2010 earthquake at Mentawai Western of Sumatra has been investigated. The observation of tsunami run up is about 5.7-7.4 m at three locations in the South and North Pagai. Numerical simulation of tsunami using the source mechanism obtained from BMKG results 3.8 m of tsunami wave height, while the propagation model shows that tsunami reach Enggano and Padang for about 38 and 58 minutes close to the tsunami travel time observation. It is clearly showed that the result of run up model is lower than its observation. From the calculation of the magnitude, it is obtained that the tsunami magnitude is about 8.1. This value is higher than the moment magnitude which is only 7.4. It can be conclude that the tsunami Mentawai can be characterized as an abnormal tsunami. This tsunami can also be categorized as a Tsunami Earthquake (TsE).

Introduction
Many studies of some great earthquakes in subduction zone of Sumatera had been carried out. Those investigations have contributed significantly on the seismic hazard potential at this area. Natawidjaja, 2007 noted that the potential megathrust earthquake at the area of the subduction depends on the fault segmentation, the dimension of the locked region and the history of the earthquake. These parameters determine the strain energy accumulation area that can generate a big earthquake. Subarya et al, 2006 had been investigated the great earthquake of Aceh-Andaman (2004, Mw 9.15), while Briggs et al, 2006, investigated the Nias Simelue (2005, Mw 8.7). Both of the earthquakes were characterized by the seismic gap zone. The Aceh Earthquake was already signed by the Simeuleu Earthquake of 2002 (Mw7.4), and then the Aceh Earthquake was assumed as an earthquake-triggered of the Nias Earthquake which occurred three months later after that.

After a series of two large earthquakes in the northern zone of Sumatra, Natawidjaja et al, 2007 predicted the megathrust of Mentawai Earthquake in the south of Sumatera. This prediction based on a study of paleogeodesy and paleoseismic (Natawidjaja, 2003) that noted the last major earthquake in Mentawai had occurred in the 1300’s and 1600’s, therefore, the cycle of the Mentawai Megathrust Earthquake is about 200 years.

Most of the big earthquakes occurred at the Sumatera area generated a tsunami. Jaiswal et al., (2006), noted that there were 33 tsunamis occurred at the Sumatera area. As a part of Sunda Arc, Sumatera had been much more active than Java. Table 1 gives a list of Tsunami Occurrence in Sumatera area.

From the list of tsunami events, generally, the tsunamis in the Sumatera area are generated by an earthquake with a magnitude of more than 7 Ms. The Mentawai Earthquake which happened on Oktober 25th, 2010 is an earthquake that generated a tsunami due to its magnitude and depth. This study investigated a Mentawai Tsunami which generated by an earthquake with a magnitude of 7.2 Mw. The earthquake has occurred along the plate interface boundary between the Australia and Sunda plates at Pagai Selatan Sumatera. According to BMKG, the earthquake located at the location of 3.6oS and 99.9oE with 10 km depth. This big earthquake occurred due to the movement of the Australia Plate with respect to the Sunda Plate with a velocity of approximately 50-70 mm/yr.

The Mamoru Nakamura’s Program was applied in this study to run a modeling of the Mentawai tsunami. A field study to the Mentawai Islands after the event had also been carried out in this research to provide the height of tsunami run-up in that area to validate the tsunami modeling

The establishment of the tsunami warning system is based on the fact, that the seismic waves propagate faster then tsunami wave. The tsunami wave arrive in the shore line after the earthquake parameters can be determined, so that there is time left to evaluate the earthquake, whether the earthquake is tsunamigenic or not, disseminated the information or warning to the target area, and finally to do evacuation if necessary. For the tele-tsunami, in which the tsunami will arrive in the beach more then one hour after the origin time of earthquake, generally there is enough time to do all of those processes, so that the warning can be disseminate in 100 % confidence level. For local tsunami, in which the tsunami will arrive in the beach less then one hour, the warning is disseminated in the lower the confidence level. For example, Indonesia Tsunami Warning System (InaTEWS) is designed for local tsunami warning for Indonesian region. Any tsunami-genic earthquake occurs in the Indian Ocean plate boundary, the tsunami wave will sweep the closest shore line within 20-40 minutes after the origin time of the earthquake. The warning is determined just only based on the evaluation of the earthquake parameters and tsunami modeling. It is difficult to add sea level data to increase the confidence level of he warning. Although the confidence level is lower, the tsunami warning could be disseminated. In some cases, especially for the eastern of Indonesia, the tsunami can be generated within inner sea, such as Flores sea, Banda sea, Ceram sea, Maluku sea, and any others. In that cases, tsunami wave will reach the closest shore line within 10 minutes or less. This tsunami may be called as very local tsunami. By evaluating the time line for issuing the tsunami warning, it is clear that very critical to disseminate tsunami warning based on the available technology recently. The effectiveness of the warning is very small, therefore another possibility warning for very local tsunami should be designed. In this presentation, we propose to use natural signs as the warning. As we might know that in general tsunami can be generated by large earthquake.

This kind earthquake could be felt strongly by most peoples. This natural sign could be applied as a tsunami warning. The other possibility is to use rather simple technology, as compliment to the natural warning. A very local tsunami warning system can be designed as the following. The warning system consist of two devices, those are a three component broadband seismograph and a local siren. The seismograph can be used to monitor and estimate the magnitude of the local earthquake and the siren can be used to warn the people if the earthquake is possible to generate tsunami.
Although, the natural signs and the simple technology could be combine to establish the very local tsunami warning system, the important is to educate people so that they understand the earthquake,tsunami, and how they can save from those disasters

A mid-term precursory seismic rate changes before 2007 Bengkulu earthquake and 2009 Padang earthquake was observed. We focused in this study on analyze seismotectonic parameter and seismic rate changes over Sumatra using Matlab. Seismicity rate changes parameter is used to identify mid-term precursor. We use the catalogue of USGS and BMKG from 1973.03 up to 2009.69. From seismicity rate changes anomaly, earthquake precursor can be identified 3-1 years before M8.5-M7.9 (USGS) 13 September 2007 Bengkulu earthquake and 6-3 years before M7.5 (USGS) 30 September 2009 Padang earthquake. From seismotectonic analysis, the period of repeated earthquakes in the Sumatra region with magnitudes M6,5 varies between 5 to 22 years and M7 varies around 15 to 90 years


Pendahuluan
Sumatera-Andaman merupakan salah satu wilayah dengan aktifitas kegempaan yang sangat tingi. Salah satu gempa terbesar di dunia Mw 9,0 pernah terjadi di wilayah ini pada 26 Desember 2004, disusul gempa nias Mw 8,7 pada 28 Maret 2005. Para ahli seismologi di dunia telah melakukan penelitian-penelitian mengenai proses gempabumi, salah satunya adalah relasi frekuensi-magnitude yang dikemukakan oleh Gutenberg-Richter (1964). Relasi frekuensi-magnitude dari gempabumi, pertama kali dikemukakan oleh Ishimoto and Iida (1939) serta Gutenberg Ricther (1964). Relasi ini merupakan hubungan pangkat (power law). Banyak ahli menyatakan bahwa nilai-b bergantung pada karakter tektonik dan tingkat stress atau struktur material suatu wilayah (Scholz, 1968; Hatzidimitriou, 1985; Tsapanos, 1990). Variasi nilai-b suatu wilayah berhubungan dengan heterogenitas struktur dan distribusi stress wilayah tersebut (Scholtz, 1968; Biswas, 1988). Secara statistik perubahan nilai-b yang signifikan telah teramati di beberapa regime stress seperti zona subduksi lempeng dan zona patahan.

Prekursor seismik merupakan sesuatu hal yang penting meskipun masih menjadi topik yang banyak diperdebatkan sampai saat ini antara yang setuju dan tidak. Salah satu prekursor yang dipelajari saat ini adalah ketenangan seismik (seismic quiescence). Seismic quiescence dikemukakan pertama kali oleh Wyss dan Habermann (1988) dengan hipotesanya bahwa beberapa gempa utama diawali dengan kehadiran seismic quiescence dimana terjadi penurunan yang signifikan dari rata rata tingkat seismisitasnya.
Penelitian ini bertujuan menganalisa prediktabilitas gempabumi dalam skala waktu menengah di daerah Sumatera menggunakan metode perubahan tingkat kegempaan dengan mengambil studi kasus gempa gempa besar yang terjadi di wilayah Sumatera pada tahun-tahun terakhir ini antara lain gempabumi Bengkulu 13 September 2007 dan gempabumi Padang 30 September 2009.

On September 28, 2009, at 2:55 PM local time, a M 7.3 earthquake struck Tasikmalaya distric, West Java province. Occurring 142 km WSW of Tasikmalaya, Java at a depth of 30km. A tsunami warning was issued but withdrawn one hour later. The main shock and several aftershocks caused 64.413 structures, including houses and bridges, to collapse or suffer significant damage in Tasikmalaya, Cianjur, Garut,Sukabumi,Bandung, West Bandung, Bogor, Kuningan, Ciamis, Banjar, Purwakarta, Majalengka and Subang, which in turn caused at least 82 deaths.


To be continued...

I am sure you certainly knew what is the Google Talk. With Google talk, you can send instant messages, make voice calls, leave voicemail also transfer files etc, but of course must be with the Google users. Now, you can add Google talk to your blog. Please follow the step below :

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