The Godzilla Megamullion ( ja, ゴジラ・メガムリオン, Gojira megamurion) is an undersea Japanese

megamullion An oceanic core complex, or megamullion, is a seabed geologic feature that forms a long ridge perpendicular to a mid-ocean ridge. It contains smooth domes that are lined with transverse ridges like a corrugated roof. They can vary in size from 10 ...

, or oceanic core complex, south-east of the island of

Okinotorishima , or Parece Vela, is a coral reef with two rocks enlarged with tetrapod-cement structures. It is administered by Japan with a total shoal area of and land area . Its dry land area is mostly made up by three concrete encasings and there is a st ...

in the

Philippine Sea The Philippine Sea is a marginal sea of the Western Pacific Ocean east of the Philippine archipelago (hence the name), the largest in the world, occupying an estimated surface area of . The Philippine Sea Plate forms the floor of the sea. Its ...

. It is about long by wide, and is the largest known oceanic core complex in the world. Due to its size it is named after the fictional monster

Godzilla is a fictional monster, or '' kaiju'', originating from a series of Japanese films. The character first appeared in the 1954 film ''Godzilla'' and became a worldwide pop culture icon, appearing in various media, including 32 films produc ...

, and 14 individual topographic features have been named after Godzilla's body parts.

Description

The Godzilla Megamullion is to the south-east of

, the southernmost island of Japan. It is part of the Parece Vela Rift in the

, between

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

in the western Pacific Ocean. The megamullion is dome-shaped, and is named after

as it is the largest known oceanic core complex, measuring approximately , more than ten times the size of the next largest known oceanic core complex. It is also the first known megamullion in a

back-arc basin A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of ...

, which is unique as most megamullions form on slow-spreading mid-ocean ridges. Sampling of the megamullion lithology yielded mostly

peridotite Peridotite ( ) is a dense, coarse-grained igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium (Mg2+), reflecting the high prop ...

gabbroic Gabbro () is a phaneritic (coarse-grained), mafic intrusive igneous rock formed from the slow cooling of magnesium-rich and iron-rich magma into a holocrystalline mass deep beneath the Earth's surface. Slow-cooling, coarse-grained gabbro is che ...

rocks,

leucocratic In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, whi ...

rocks, and

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

. The gabbroic rocks and peridotite are present throughout the entire length of the megamullion's flow line, indicating that the megamullion is a

detachment fault A detachment fault is a gently dipping normal fault associated with large-scale extensional tectonics. Detachment faults often have very large displacements (tens of km) and juxtapose unmetamorphosed hanging walls against medium to high-grade me ...

that exposes the uppermost mantle and lower

oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumu ...

. The megamullion has abundant

plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more prope ...

bearing peridotite.

Discovery and exploration

The Godzilla Megamullion was discovered in 2001 as part of the Continental Shelf Surveys Project of the

Hydrographic and Oceanographic Department of Japan Hydrographics may refer to: *Hydrography, the measurement of physical characteristics of waters and marginal land *Hydrographics (printing), a printing technique for three-dimensional objects * Hydrographic Department, UK agency for providing hydr ...

, and was first described by Yasuhiko Ohara. It was initially named as the "Giant Megamullion". Since 2001 more than 20 expeditions have explored the megamullion. Due to the large size of the megamullion, when describing features it is often divided into

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

, medial, and

proximal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

parts. Names describing Godzilla's body parts have also been given to 14 topographic features (south-west to north-east): West Leg Ridge, South Tail Rise, East Leg Ridge, West Hipbone Rise, North Tail Rise, East Hipbone Rise, West Arm Rise, Backbone Rise, East Arm Rise, West Shoulder Ridge, Neck Peak, East Shoulder Ridge, Head Peak, Hat Ridge.

Naming

Godzilla King of the Monsters (1956) Profile

The

Japan Coast Guard The is the coast guard of Japan. The Japan Coast Guard consists of about 13,700 personnel and is responsible for the protection of the coastline of Japan under the oversight of the Ministry of Land, Infrastructure, Transport and Tourism. Th ...

helped to name the megamullion, reaching an agreement with

Toho is a Japanese film, theatre production and distribution company. It has its headquarters in Chiyoda, Tokyo, and is one of the core companies of the Osaka-based Hankyu Hanshin Toho Group. Outside of Japan, it is best known as the producer an ...

, who own the rights to the character

. Toho's chief Godzilla officer Keiji Ota stated: "I am truly honored that he megamullionbears Godzilla's name, the Earth's most powerful monster."

References

{{coord, 16, 00, N, 139, 20, E, region:JA, display=title Oceanic ridges Landforms of Japan Philippine Sea Geology of the Pacific Ocean