|Solomon Sea Plate|
|Approximate area||250,000 km2|
|1Relative to the African Plate|
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 resulting volcanism. The southwestern subduction zone is where the Solomon Pate is diving below the Indo-Australian Plate.
The 1971 Solomon Islands earthquakes occurred in the northern part of the Solomon Islands, within Papua New Guinea as a doublet earthquake. The first large shock occurred on July 14 at 06:11 UTC with a magnitude of Mw 8.0. The second large event occurred on July 26 at 01:23 UTC with a magnitude of Mw 8.1. The initial event on July 14 caused a tsunami, which was observed in Rabaul. The earthquake of July 26 triggered a tsunami with a 3.4 m (11 ft) runup in New Britain.Shallow, large thrust earthquakes in the Solomon Islands tend to occur in multiplets. Examples of such earthquakes include the doublets occurred in 1971, 1974, and 1975. The 1971 doublet occurred at the junction of two trenches. The July 14 earthquake is located in the northwestern Solomon Islands Trench, while the July 26 earthquake ruptured the northeastern New Britain Trench. The July 14 earthquake and the July 26 earthquake were caused by the subduction of the Solomon Sea Plate beneath the Pacific Plate and the Bismark Sea Plate, respectively. The 1971 sequence had the largest earthquake in 50 years in this region as it occurred.2007 Solomon Islands earthquake
The 2007 Solomon Islands earthquake took place on 2 April 2007, near the provincial capital of Gizo on Ghizo Island, in Solomon Islands. Its magnitude was estimated at 8.1 on the Mw scale, and 7.8 on the Ms scale. The tsunami that followed the earthquake killed 52 people. According to the USGS, the earthquake was recorded around 7:39:56 a.m. local time (UTC+11). The focus was 10 km (6 mi) deep and 40 km (25 mi) South South-East of Gizo township on New Georgia Islands in Western Province. There were numerous aftershocks, the largest of which had a magnitude of 6.2.Carteret Islands
The Carteret Islands (also known as Carteret Atoll, Tulun or Kilinailau Islands/Atoll) are Papua New Guinea islands located 86 km (53 mi) north-east of Bougainville in the South Pacific. The atoll has a scattering of low-lying islands called Han, Jangain, Yesila, Yolasa and Piul, in a horseshoe shape stretching 30 km (19 mi) in north-south direction, with a total land area of 0.6 square kilometres (0.2 sq mi) and a maximum elevation of 1.5 metres (4 ft 11.1 in) above sea level.
The group is made up of islands collectively named after the British navigator Philip Carteret, who was the first European to discover them, arriving in the sloop Swallow in 1767.As of 2005, about one thousand people live on the islands. Han is the most significant island, with the others being small islets around the lagoon. The main settlement is at Weteili on Han. The island is near the edge of the large geologic formation called the Ontong Java Plateau.Cotabato Trench
The Cotabato Trench is an oceanic trench in the Pacific Ocean, off the southwestern coast of Mindanao in the Philippines. Along this trench the oceanic crust of the Sunda Plate beneath the Celebes Sea is being subducted beneath the Philippines Mobile Belt. It forms part of a linked
set of trenches along the western side of the Philippines formed over east-dipping subduction zones, including the Manila Trench and the Negros Trench. At its northern end the rate of convergence across this boundary is about 100 mm per year. It is a relatively young structure, forming during the late Miocene to Pliocene. This age is consistent with the estimated age of the sedimentary rocks in the accretionary wedge associated with the trench and the age of adakitic arc rocks on Mindanao thought to date the onset of subduction.Geology of the Pacific Ocean
The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific Plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth.The tectonic plates continue to move today. The slowest spreading ridge is the Gakkel Ridge on the Arctic Ocean floor, which spreads at less than 2.5 cm/year (1 in/year), while the fastest, the East Pacific Rise near Easter Island, has a spreading rate of over 15 cm/year (6 in/year).Lae
Lae () is the capital of Morobe Province and is the second-largest city in Papua New Guinea. It is located near the delta of the Markham River and at the start of the Highlands Highway, which is the main land transport corridor between the Highlands region and the coast. Lae is the largest cargo port of the country and is the industrial hub of Papua New Guinea. The city is known as the Garden City and home of the University of Technology.List of tectonic plates
This is a list of tectonic plates on the Earth's surface. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium). The composition of the two types of crust differs markedly, with mafic basaltic rocks dominating oceanic crust, while continental crust consists principally of lower-density felsic granitic rocks.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), 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.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. 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.Marikina Valley Fault System
The Marikina Valley Fault System, also known as the Valley Fault System (VFS), is a dominantly dextral strike-slip fault system in Luzon, Philippines. It extends from Doña Remedios Trinidad, Bulacan in the north and runs through the provinces of Rizal, and the Metro Manila cities of Quezon, Marikina, Pasig, Makati, Taguig and Muntinlupa, and the provinces of Cavite and Laguna that ends in Canlubang.Ring of Fire
The Ring of Fire (also known as the Rim of Fire or the Circum-Pacific belt) is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. In a large 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes).About 90% of the world's earthquakes and about 81% of the world's largest earthquakes occur along the Ring of Fire. All but three of the world's 25 largest volcanic eruptions of the last 11,700 years occurred at volcanoes in the Ring of Fire. The Ring of Fire is a direct result of plate tectonics: the movement and collisions of lithospheric plates, especially subduction in the northern portion. The western portion is more complex, with a number of smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Bougainville, Tonga, and New Zealand.Solomon Sea
The Solomon Sea is a sea located within the Pacific Ocean. It lies between Papua New Guinea and the Solomon Islands. Many major battles were fought there during World War II.Woodlark Plate
The Woodlark Plate is a small tectonic plate located in the eastern half of the island of New Guinea. The Caroline plate subducts 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.