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Abstrak :
Over the past few years, devastating tsunamis off the coast of the Indian Ocean have killed hundreds of thousands of people. Even more alarmingly, scientists predict that these tsunamis, as well as a series of earthquakes and volcanic eruptions, may eventually threaten Hawaii, California, and Oregon. The cause of this trinity of natural disasters is plate tectonics. Perhaps the greatest advance made in the field of earth science, the plate-tectonics theory argues that the surface of the Earth is broken into large plates, which change in size and position over time.

Abstrak :
Proses Micro Friction Stir Spot Welding (MFSSW) merupakan sebuah teknik pengelasan pelat logam dengan ketebalan pelat yang relatif tipis. Keunggulan dari pengelasan ini adalah kualitas hasil pengelasan yang lebih tinggi dan deformasi yang relatif rendah. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh bentuk pahat dan kedalaman tusuk pahat kepada kecenderungan aliran material pada struktur makro hasil lasan yang dihasilkan pada teknik Micro Stir Spot Welding (MFSSW) dengan menggunakan pelat tipis Alumunium AA1100. Pada penelitian ini parameter yang diubah adalah geometri pahat dan kedalaman pahat. Dalam penelitian ini parameter geometri pahat dibagi menjadi 7 jenis geometri pahat dan parameter kedalaman tusuk dibagi menjadi 3 kedalaman (200 mikron, 400 mikron dan 600 mikron). Uji makro dilakukan untuk mengetahui kedalaman lasan, profil kontur, dan makrostruktur bentangan dari hasil lasan. Hasil uji makro akan digunakan untuk menganalisis hubungan hook pada setiap zona lasan pada hasil pengelasan dari setiap tools yang ada. ......The Micro Friction Stir Spot Welding (MFSSW) process is a metal plate welding technique with a relatively thin plate thickness. The advantages of this welding are the higher quality of the welds and the relatively low deformation. The purpose of this study was to determine the effect of the chisel shape and the depth of the chisel on the material flow tendency in the macrostructure of the welds produced in the Micro Stir Spot Welding (MFSSW) technique using a thin plate of aluminum AA1100. In this research, the parameters that are changed are the tool geometry and plunge depth. In this study, the tool geometry parameters were divided into 7 types of tool geometries and the plunge depth parameters were divided into 3 depths (200 microns, 400 microns, and 600 microns). A macro test is performed to determine the depth of the weld, the contour profile, and the macrostructure of the expanse of the weld. The macro test results will be used to analyze the hook relationship at each weld zone on the welding results of each existing tool

Abstrak :
Indonesia diampit dengan tiga lempeng Eurasia, Pasifik, dan Indo-Australia. Berdasarkan teori tektonik lempeng, pergerakan lempeng disebabkan oleh adanya dorongan dari arus konveksi mantel. Teori tersebut menyebabkan Indonesia mempunyai struktur-struktur geologi yang kompleks. Studi geologi struktur perlu dilakukan untuk mengetahui keadaan bawah permukaan. Mencari struktur sulit dilakukan maka dari itu, dibutuhkan metode yang tepat dalam memetakan keberadaan struktur geologi. Metode tersebut adalah atribut seismik. Penelitian ini memakai data seismik 2D sebanyak 11 lintasan. Seismik 2D dapat dimodifikasi menjadi seismik volume menggunakan Pseudo 3D sehingga dapat dilakukan atribut seismik dalam mencari struktur geologi. Metode atribut seismik yang tepat dalam memetakan struktur geologi yaitu atribut seismik curvature, coherence, dan variance. Selanjutnya, menentukan atribut terbaik dalam memetakan struktur geologi yaitu variance dan membuat surface horizon map untuk mengetahui ketinggian secara lateral. Selanjutnya, melakukan intrepretasi secara manual dengan bantuan atribut seismik variance dan menganalisis orientasi arah major fault dan gaya utama. Dengan didapat orientasi major fault Timur Laut – Barat Daya dan gaya utama berasal dari Utara – Selatan mendorong ke tengah. Selain itu, dilihat spektrum frekuensi setelah dan sebelum dilakukan Pseudo 3D untuk melihat pengaruh Pseudo 3D terhadap data seismik. Dengan hasil yang dikeluarkan berbeda frekuensi setelah dan sebelum Pseudo 3D sehingga proses Pseudo 3D mempengaruhi kualitas data seismik. ......Indonesia is flanked by three plates Eurasia, Pacific, and Indo-Australian. Based on plate tectonic theory, plate movement is caused by nudge from mantle convection current. This theory causes Indonesia to have complex geological structures. Structural Geological studies to be done to determine the sub-surface state. Finding geological structures is difficult, therfore, it takes the right method in mapping the existence of geological structures. The method is a seismic attribute. This study used 11 lines 2D seismic. 2D seismic data can be modified into seismic volumes using Pseudo 3D so that seismic attributes can be performed in search of geological structures. Precise seismic attribute methods in mapping geological structures are curvature, coherence, and variance seismic attributes. Furthermore, determine the best attributes in mapping geological structures namely variance and create a surface horizon map to know the altitude laterally. Next, perform the interpretation manually, with the help of variance seismic attribute and then analyze the orientation of major fault direction and main force. With the orientation of the major fault Northeast – Southwest and main force originating from North – South pushes to the center. In addition, look at the frequency spectrum before and after Pseudo 3D is performed to see the influence of Pseudo 3D on seismic data. With the results issued different frequencies before and after Pseudo 3D so that the Pseudo 3D procces affects the quality of seismic data.

Abstrak :
It begins by solving a famous puzzle of the ancient world, which is what was responsible for the tsunami that destroyed settlements in the eastern Mediterranean in 365 AD. By radiocarbon dating of preserved marine organisms, Shaw demonstrates that the whole of western Crete was lifted out of the sea by up to 10 meters in a massive earthquake at that time, which occured on a previously unknown fault. The author shows that the resulting tsunami would have the characteristics described by ancient writers, and uses modern GPS measurements and coastline geomorphology to show that the strain build-up near Crete requires such a tsunami-earthquake about every 6.000 years. A detailed seismological study of earthquakes in the Cretan arc over the last 50 years reveals other important features of its behaviour that were previously unknown. Finally, she provides fundamental insights into the limitations of radiocarbon dating marine organisms, relating to how they secrete carbon into their skeletons.