Manila Trench
The Manila Trench is an oceanic trench in the Pacific Ocean, located west of the islands of Luzon and Mindoro in the Philippines. The trench reaches a depth of about 5,400 metres (17,700 ft),[1] in contrast with the average depth of the South China Sea of about 1,500 metres (4,900 ft). It is created by subduction, in which the Sunda Plate (part of Eurasian Plate) is subducting under the Philippine Mobile Belt, producing this almost N-S trending trench. The convergent boundary is terminated to the north by the Taiwan collision zone, and to the south by the Mindoro terrane (Sulu-Palawan block colliding with SW Luzon). It is an area pervaded by negative gravity anomalies.[2]
The Manila Trench is associated with frequent earthquakes, and the subduction zone is responsible for the belt of volcanoes on the west side of the Philippine island of Luzon, which includes Mount Pinatubo.
Convergence between the Philippine Mobile Belt and the Sunda Plate have been estimated using GPS measurements, and this value ranges from ~ 50+ mm/yr in Taiwan, to 100 mm/yr near N. Luzon, and ~ 50 mm/yr near Zambales and ~20+mm/yr near Mindoro island.[3] Plate locking between the Sunda Plate and Luzon is about 1% coupled, almost unlocked as determined by elastic block models, suggesting that the trench absorbs the Philippine Mobile Belt-Eurasian Plate convergence.[4]
Notes
References
- Bowin, C; Lu, RS; Lee, CS; Schouten, H (1978). "Plate Convergence and Accretion in Taiwan-Luzon Region". Am. Assoc. Pet. Geol. Bull 62: 1645–1672. doi:10.1306/C1EA5260-16C9-11D7-8645000102C1865D.
- Hayes, DE; Lewis, SD (1984). "A geophysical study of the Manila trench, Luzon, Philippines. 1. Crustal structure, gravity and regional tectonic evolution". J. Geophys. Res. 89 (B11): 9171–9195. doi:10.1029/JB089iB11p09171.
- Galgana, G; Hamburger, M; McCaffrey, R; Corpuz, E; Chen, Q (2007). "Analysis of crustal deformation in Luzon, Philippines using geodetic observations and earthquake focal mechanisms". Tectonophysics (432): 63–87. doi:10.1016/j.tecto.2006.12.001.
- Kreemer, C; Holt, WE (2001). "A no-net-rotation model of present-day surface motions". Geophys Res Lett 28: 4407–4410. doi:10.1029/2001GL013232.
- Liu, Y; Santos, A; Wang, S; Shi, Y; Liu, H; Yuen, DA (2007). "Tsunami hazards along Chinese coast from potential earthquakes in South China Sea (preprint)". Physics of The Earth and Planetary Interiors 163 (1-4): 233–244. doi:10.1016/j.pepi.2007.02.012.
- Rangin, C; Le Pichon, X; Mazzotti, S; Pubellier, M; Chamot-Rooke, N; Aurelio, M Walpersdorf, A; Quebral, R (1999). "Plate convergence measured by GPS across the Sundaland/Philippine Sea Plate deformed boundary: the Philippines and eastern Indonesia". Geophysical Journal International (Taiwan Geological Survey) 139: 296–316.
External links
- "Cenozoic Plate Tectonic Setting". Central Geological Survey, MOEA. Retrieved March 2011.
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Coordinates: 14°42′N 119°00′E / 14.700°N 119.000°E