Benham Rise

ThePhilippine Rise(Filipino:Talampas ng Pilipinas), formally designated asBenham Rise,is anextinct volcanic ridgelocated in thePhilippine Seaapproximately 250 kilometers (160 mi) east of the northern coastline ofDinapigue, Isabela. The feature has long been known to the people ofCatanduanesasKalipung-awan, which literally means “loneliness from an isolated place”, since theprecolonial era.
Under the Philippine Sea lie a number of basins including theWest Philippine Basin, inside of which is located theCentral Basin Fault(CBF).Philippine Rise is located in the CBF and its geologicbasementis probably amicro-continent.Several scientific surveys have been made on the feature to study its nature and its impact ontectonicsubduction, including one about its effects on the1990 Luzon earthquake.
The Philippines claimed this feature as part of itscontinental shelfin a claim filed with theUnited NationsCommission on the Limits of the Continental Shelf on April 8, 2009, and which was approved under theUnited Nations Convention on the Law of the Sea(UNCLOS) in 2012.The rise is designated as a “protected food supply exclusive zone” by the Philippine government since May 2017. Mining andoil explorationare banned in the area as it is protected. The feature was renamed as "Philippine Rise" by Executive Order No. 25 on May 16, 2017and by The Philippine Maritime Zones Act on November 8, 2024.
The landform was presumably named afterAdmiral Andrew Ellicot Kennedy Benham(1832–1905) byAmericansurveyors who probably studied the geological feature. He was aUnited States Navyofficer, who served with both the South Atlantic and West Gulf Blockading Squadrons during theAmerican Civil War.
There has been speculation in the scientific community about the nature of the landform. Following the major July 161990 Luzon earthquake, scientists reconsidered their fault models and decided it likely that Philippine Plateau has similarly displaced thePhilippine Fault Systemto the west.After analyzing older models such as that of Pinet and Stephan (1989), scientists reconsidered their fault models. They thought it highly likely that the Philippine Plateau is still displacing theCentral Luzonand thePhilippine Fault Systemto the west, which may have been a factor in such a catastrophic earthquake. The 20- to 50-second wave of the 1990 quake that developed a new east–west sub-fault was so strong that it terminated disastrously in the city ofBaguioinBenguet,Cordillera. Several scientific surveys, conducted between 2004 and 2008, collected hydrographic data that determined the morphology of the seabed in the region.
Despite its proximity to the archipelago, the plateau was previously not included in charted territory of the country. On April 8, 2009, the Republic of the Philippines lodged a partialterritorial watersclaim with theUnited Nations Commission on the Limits of the Continental Shelfin relation to the continental shelf in the region of the Philippine Rise.It was submitted as part of petition expanding the archipelago's baselines andexclusive economic zonethrough a law that also included other claims involving disputed territories of the Kalayaan Islands (Spratly Islands) andScarborough Shoal.
Congressthen enacted the bill ofSenatorMiriam Defensor Santiago, now known as Republic Act No. 9522, or the Archipelagic Baselines Law, as the basis of the claim. It asserted that, according to scientific data based on seismic, magnetic, other geological features, the Philippine Rise is an extension of the Philippines’ continental shelf.The claim is only a partial claim since the law that allows the Philippines to expand its territorial boundaries also includes islands in theSouth China Sea.
The Philippines filed its claim for Benham Rise in 2008 in compliance with the requirements of theUnited Nations Convention on the Law of the Seas. The UN officially approved the claim in April 2012 underthe administrationof PresidentBenigno Aquino III. It was the first claim of the Philippines approved by an international body since the colonial era.
AfterChinesesurvey ships were spotted in the region in 2017, Philippine presidentRodrigo Dutertesuggested that the plateau be renamed to emphasize Philippine sovereignty over the area. Soon after, theDepartment of Foreign Affairsannounced plans to come up with a new name.In May 2017, the Philippine government officially adopted the name “Philippine Rise” for the featureand designated the area as a “protected food supply exclusive zone” and prohibited mining and oil exploration in the Philippine Plateau, angering China in the process. China maintained that the Philippines has no sovereign rights or sovereignty over the Philippine Rise despite a UN-backed international ruling in 2012 that says otherwise.
In January 2018, Filipino Congressman Gary Alejano revealed that theDepartment of Foreign Affairshad approved the Chinese Institute of Oceanology of theChinese Academy of Sciencestogether with the Marine Science Institute of theUniversity of the Philippinesto perform a scientific survey of the Rise.
In February, Duterte‘sSecretary of AgricultureEmmanuel Piñoltold media the President had ordered the halting of all foreign research in the Philippine Rise;however, that conducted by theChinese Academy of Scienceswas already finished two days before the order.
On February 12, 2018, theInternational Hydrographic Organizationapproved the names proposed by China for five features in the Philippine Rise after China had submitted its findings to the organization. The names given by China were all in Chinese, namely,JinghaoSeamount (some 70 nautical miles east of Cagayan),TianbaoSeamount (some 70 nautical miles east of Cagayan),HaidonquingSeamount (east at 190 nautical miles),CuiqiaoHill, andJujiuSeamount, the last two form the central peaks of the Philippine Rise undersea geological province. The Chinese naming of the features was met public protests in the Philippines.Malacañang Palaceannounced it objection, and non-recognition of the Chinese names, adding it will appeal for their rejection with the International Hydrographic Organization. The Philippine government also said their embassy in Beijing will coordinate with the Chinese government on the issue.The Palace announced the following day that government intended to give Philippine names to the features of the Philippine Rise.However, a few hours later, Presidential SpokespersonHarry Roqueclarified that China’s renaming of sea features “was a scientific process and not a political one”, adding “Whoever made the discovery gets to decide what these are called.”
On February 16, the Philippine government announced they have sent military personnel into theCagayan Valleyto guard the Rise.Two days later, it was revealed that China intended to name a total of 142 features.On February 26, the Department of Foreign Affairs stated during a Senate investigation that China actually surveyed the Rise in 2017 without any Philippine-issued permit, citing the lack of capability to detect illegal entry.
The world’s largest caldera with a diameter of 150 kilometers was discovered by Jenny Anne Baretto, a Filipino marine geophysicist. It was named after Apolaki, a precolonial god of the sun and war.
Philippine Rise is a submergedextinct volcanic ridgelocated at 16.5°N, 124.7°E off the coast ofLuzon, with the size of about 250 km in diameter and rises over 2,000 meters (2 km.) above the sea floor, from below 5,000 meters (5 km.) below sea level to above 3,000 meters (3 km.) below sea level. Its area is close to the Philippine Seamount, located at 15.8°N, 124.2°E. The precise location is somewhere near the east of thePhilippine Trenchand near the south of theEast Luzon Trench, both of which absorb the subducting force of thePhilippine Sea Plateunder thePhilippine Mobile Belt,a collage of large blocks of that crust that amalgamated prior to the collision of the Philippine Sea Plate with theEurasian Plate.
The origin of the landform, along with the nearby Urdaneta Plateau (a remnant of amantle plume), is identified in one study as at least five sequences ofpropagating rifts, probably triggered bymantleflowing away from the mantle thermal anomaly.Its presence of the landform disrupts the continuity of this region (known as the Philippine-East Luzon Trench) by continuously colliding with theSierra Madre mountain rangeof eastern portion of the island ofLuzon. Though it is generally thought that the Philippine Sea Plate is being subducted under thePhilippine Mobile Belt, under the rules oftectonicsubduction, there appears to be a resistance to this because of the presence of the landform, and instead, the plate is being displaced into the northern portion of Luzon to the west.
The geophysical features of the plateau may have been the result of an earlyMiocenecollision event between the Philippine Rise and the eastern margin of Luzon, which may have also allowed the inception of the NW striking strand of the Philippine fault.These forces may have impacted the shape of the island ofLuzonbecause of thebasalticsea floor resisting the subduction that may have also cause the bending of thePhilippine Fault.The active basins inCentral Luzon, which trace an asymmetrical V shape, is the best place to observe recent tectonic evolution of the fault system.
TheBenham Bankis the shallowest point of the Philippine Rise.
The Philippine Rise has long been part of Filipino culture, particularly of people native toCatanduaneswho have explored and fished the area long before the colonial era. CalledKalipung-awan(roughly translated from theBikol languagesas “loneliness in an isolated place”) is celebrated in Catandunganons literature, and a large portion of fish caught in the region come from the waters covering the Philippine Rise. Its poetic name come from fisherfolk who spend days in the vast and lonely waters seldom visited by other ethnic groups. Its location east ofLuzon, southeast ofTaiwan, and west of the United StatesterritoryofGuamalso makes gives it strategicgeopoliticalimportance.
In May 2017, the feature was designated by the Philippines as a “protected food supply exclusive zone”, prohibiting mining and oil exploration.To commemorate the first anniversary of the Philippine government’s renaming of the feature, 500 square kilometers (190 sq mi) of the feature was declared a “Strict Protection Zone” reserved exclusively for scientific research, while about 3,000 square kilometers (1,200 sq mi) was designated a “Special Fisheries Management Area“.