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1996 Biak Earthquake
The 1996 Biak earthquake, or the Irian Jaya earthquake, occurred on 17 February at near Biak Island, Indonesia. The earthquake, which occurred on the New Guinea Trench, had a moment magnitude of 8.2 and a maximum Mercalli intensity of IX (''Violent''). The run-up height of the generated tsunami reached . The disaster left at least 108 people dead, 423 injured, and 58 missing. It damaged or destroyed 5,043 houses which subsequently made another 10,000 homeless. At Korim, 187 houses were destroyed. Various countries and organizations provided aid and relief in the aftermath of the earthquake. Tectonic setting New Guinea lies within a very complex tectonic regime surrounded by microplates which accommodate the collision and oblique convergence between the Australian Plate and the Pacific Plate. In the north, the Caroline Plate and North Bismarck Plate subduct underneath the Bird's Head Plate and the Woodlark Plate along the New Guinea Trench. The earthquake occurred at the cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time In Indonesia
The Indonesian Archipelago geographically stretches across four time zones from UTC+06:00 in Aceh to UTC+09:00 in Papua. However, the Indonesian government recognises only three time zones in its territory, namely: *Western Indonesia Time (WIB) — seven hours ahead ( UTC+07:00) of the Coordinated Universal Time (UTC); *Central Indonesia Time (WITA) — eight hours ahead ( UTC+08:00) of UTC; *Eastern Indonesia Time (WIT) — nine hours ahead ( UTC+09:00) of UTC. The boundary between the Western and Central time zones was established as a line running north between Java and Bali through the provincial boundaries of West and Central Kalimantan. The border between the Central and Eastern time zones runs north from the eastern tip of Indonesian Timor to the eastern tip of Sulawesi. Daylight saving time (DST) is no longer observed anywhere in Indonesia. Current usage In Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodlark Plate
The Woodlark Plate is a small tectonic plate located in the eastern half of the island of New Guinea. It subducts beneath the Caroline plate along its northern border while the Maoke Plate converges on the west, the Australian plate converges on the south, and on the east an undefined compressive zone which may be a transform fault marking the boundary with the adjoining Solomon Sea Plate. It also contacts the South Bismarck Plate The South Bismarck Plate is a small tectonic plate located in the southern Bismarck Sea. The eastern part of New Guinea and the island of New Britain are on this plate. Tectonics Convergent boundaries line the southern border including the subdu ... due northeast. See also * References * Tectonic plates Geology of the Pacific Ocean {{tectonics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousands of instrumentally detectable aftershocks, which steadily decrease in magnitude and frequency according to a consistent pattern. In some earthquakes the main rupture happens in two or more steps, resulting in multiple main shocks. These are known as doublet earthquakes, and in general can be distinguished from aftershocks in having similar magnitudes and nearly identical seismic waveforms. Distribution of aftershocks Most aftershocks are located over the full area of fault rupture and either occur along the fault plane itself or along other faults within the volume affected by the strain associated with the main shock. Typically, aftershocks are found up to a distance equal to the rupture length away from the fault plane. The pattern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocenter
In seismology, a hypocenter or hypocentre () is the point of origin of an earthquake or a subsurface nuclear explosion. A synonym is the focus of an earthquake. Earthquakes An earthquake's hypocenter is the position where the strain energy stored in the rock is first released, marking the point where the fault begins to rupture.''The hypocenter is the point within the earth where an earthquake rupture starts. The epicenter is the point directly above it at the surface of the Earth. Also commonly termed the focus.'' This occurs directly beneath the epicenter, at a distance known as the ''hypocentral depth'' or ''focal depth''. The focal depth can be calculated from measurements based on seismic wave phenomena. As with all wave phenomena in physics, there is uncertainty in such measurements that grows with the wavelength so the focal depth of the source of these long-wavelength (low frequency) waves is difficult to determine exactly. Very strong earthquakes radiate a large fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Trench
Oceanic trenches are prominent long, narrow topographic depressions of the ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic trenches worldwide, mostly around the Pacific Ocean, but also in the eastern Indian Ocean and a few other locations. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of below sea level. Oceanic trenches are a feature of the Earth's distinctive plate tectonics. They mark the locations of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to and about from a vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake Rupture
In seismology, an earthquake rupture is the extent of slip that occurs during an earthquake in the Earth's crust. Earthquakes occur for many reasons that include: landslides, movement of magma in a volcano, the formation of a new fault, or, most commonly of all, a slip on an existing fault. Nucleation A tectonic earthquake begins by an initial rupture at a point on the fault surface, a process known as nucleation. The scale of the nucleation zone is uncertain, with some evidence, such as the rupture dimensions of the smallest earthquakes, suggesting that it is smaller than 100 m while other evidence, such as a slow component revealed by low-frequency spectra of some earthquakes, suggest that it is larger. The possibility that the nucleation involves some sort of preparation process is supported by the observation that about 40% of earthquakes are preceded by foreshocks. However, some large earthquakes, such as the M8.6 1950 India - China earthquake., have no foreshocks and it re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike And Dip
Strike and dip is a measurement convention used to describe the orientation, or attitude, of a planar geologic feature. A feature's strike is the azimuth of an imagined horizontal line across the plane, and its dip is the angle of inclination measured downward from horizontal. They are used together to measure and document a structure's characteristics for study or for use on a geologic map. A feature's orientation can also be represented by dip and dip direction, using the azimuth of the dip rather than the strike value. Linear features are similarly measured with trend and plunge, where "trend" is analogous to dip direction and "plunge" is the dip angle. Strike and dip are measured using a compass and a clinometer. A compass is used to measure the feature's strike by holding the compass horizontally against the feature. A clinometer measures the features dip by recording the inclination perpendicular to the strike. These can be done separately, or together using a tool such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Mechanism
The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is also known as a fault-plane solution. Focal mechanisms are derived from a solution of the moment tensor for the earthquake, which itself is estimated by an analysis of observed seismic waveforms. The focal mechanism can be derived from observing the pattern of "first motions", that is, whether the first arriving P waves break up or down. This method was used before waveforms were recorded and analysed digitally and this method is still used for earthquakes too small for easy moment tensor solution. Focal mechanisms are now mainly derived using semi-automatic analysis of the recorded waveforms. Moment tensor solutions The moment tensor solution is typically displayed graphically using a so-called ''beachball'' diagram. The pattern of en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solomon Sea Plate
The Solomon Sea Plate is a minor tectonic plate to the northwest of the Solomon Islands archipelago in the south Pacific Ocean. Itt roughly corresponds with the Solomon Sea east of Papua New Guinea. Tectonics The tectonic regime in this part of the world is extremely complex and involves a number of minor as well as major plates. The Solomon Sea Plate is an oceanic crustal plate remnant which is disappearing into two subduction zones, one to its north, the other on its southwest margin. Its southeast margin runs along the Woodlark Rise, an undefined compressive zone which may be a transform fault marking the boundary with the adjoining Woodlark Plate. The northern subduction zone is located where the Solomon Plate is diving below the South Bismarck Plate to the northwest and the Pacific Plate to the northeast. The northwest part of the subduction zone is called the New Britain Subduction Zone. New Britain in Papua New Guinea is the volcanic island formed from this collision and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Bismarck Plate
The South Bismarck Plate is a small tectonic plate located in the southern Bismarck Sea. The eastern part of New Guinea and the island of New Britain are on this plate. Tectonics Convergent boundaries line the southern border including the subduction zone responsible for the formation of New Britain and the Solomon Islands. Many earthquakes occur in this area particularly around New Britain. GPS data shows the South Bismarck plate, though north of the Australian plate boundary, is being pushed by Australia in a northerly direction while the North Bismarck Plate is being dragged by the Pacific plate easterly. The line delineating the two is called the Bismarck Seismic Sea Lineation (BSSL), and it is not known where this line ends on the West side towards New Ireland. See also *List of earthquakes in Papua New Guinea Earthquakes in Papua New Guinea are due to its location near the geologically-active Pacific Ring of Fire. Overall, the population in this region resides in str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maoke Plate
The Maoke Plate is a small tectonic plate located in western New Guinea underlying the Sudirman Range from which the highest mountain on the island- Puncak Jaya rises. To its east is a convergent boundary with the Woodlark Plate. To the south lies a transform boundary with the Australian Plate and the Bird's Head Plate The Bird's Head Plate is a minor tectonic plate incorporating the Bird's Head Peninsula, at the western end of the island of New Guinea. Hillis and Müller consider it to be moving in unison with the Pacific Plate. Bird considers it to be unconne ... lies to the west. References * Tectonic plates Geology of Indonesia Geology of the Pacific Ocean {{tectonics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
