Thematic Article A bathymetric overview of the Mariana forearc
... shown every 1000 m and labeled every km below sea-level. The islands from Guam to Ferdinand de Medinilla manifest structural uplift along the frontal arc; active arc volcanism lies slightly to the west of the frontal arc. The Mariana Trench lies along or near the eastern limit of coverage, and can b ...
... shown every 1000 m and labeled every km below sea-level. The islands from Guam to Ferdinand de Medinilla manifest structural uplift along the frontal arc; active arc volcanism lies slightly to the west of the frontal arc. The Mariana Trench lies along or near the eastern limit of coverage, and can b ...
Global geochemical variation of mid-ocean ridge basalts - UiO
... The terms compatible and incompatible elements refer to the elements partitioning into crystal structures relative to coexisting melts. Compatible elements are elements that have higher affinity for the crystal structure of the minerals in the mantle compared to a partial melt. Therefore, compatible ...
... The terms compatible and incompatible elements refer to the elements partitioning into crystal structures relative to coexisting melts. Compatible elements are elements that have higher affinity for the crystal structure of the minerals in the mantle compared to a partial melt. Therefore, compatible ...
The deep Earth origin of the Iceland plume and
... that exhumation across northern England can be explained by topographic doming over a mantle hotspot (Lewis et al., 1992). The motion path of the Iceland plume is elusive as large ice sheets over Greenland currently mask geological evidence that could potentially resolve this debate (Rogozhina et al ...
... that exhumation across northern England can be explained by topographic doming over a mantle hotspot (Lewis et al., 1992). The motion path of the Iceland plume is elusive as large ice sheets over Greenland currently mask geological evidence that could potentially resolve this debate (Rogozhina et al ...
Kerguelen Hotspot Magma Output since 130 Ma
... another consisting of a single, but dismembered plume source. ...
... another consisting of a single, but dismembered plume source. ...
Flow and melting of a heterogeneous mantle: 2. Implications for a
... We have recently examined the importance of upper mantle flow and melting of a heterogeneous mantle on the incompatible trace element and isotope composition of ocean island basalts (OIBs) and mid-ocean ridge basalts (MORBs) [G. Ito, J. Mahoney, Flow and melting of a heterogeneous mantle 1: method a ...
... We have recently examined the importance of upper mantle flow and melting of a heterogeneous mantle on the incompatible trace element and isotope composition of ocean island basalts (OIBs) and mid-ocean ridge basalts (MORBs) [G. Ito, J. Mahoney, Flow and melting of a heterogeneous mantle 1: method a ...
1 Bathymetry of the Pacific Plate and its Implications for Thermal
... Seafloor topography (i.e., ocean depth) and heat flux are the key observations that reflect the thermal and dynamic states of the mantle and lithosphere. Seafloor topography increases with the age of seafloor (i.e., lithospheric age), while seafloor heat flux decreases with lithospheric age. Seafloo ...
... Seafloor topography (i.e., ocean depth) and heat flux are the key observations that reflect the thermal and dynamic states of the mantle and lithosphere. Seafloor topography increases with the age of seafloor (i.e., lithospheric age), while seafloor heat flux decreases with lithospheric age. Seafloo ...
Mid-Ocean Ridges: Mantle Convection and Formation
... crust. The crust and mantle cool at the surface by thermal conduction and hydrothermal circulation. This cooling generates a thermal boundary layer, which is rigid to convection and is the newly created edge of the tectonic plate. As the lithosphere moves away from the ridge, it thickens via additio ...
... crust. The crust and mantle cool at the surface by thermal conduction and hydrothermal circulation. This cooling generates a thermal boundary layer, which is rigid to convection and is the newly created edge of the tectonic plate. As the lithosphere moves away from the ridge, it thickens via additio ...
Ancient recycled mantle lithosphere in the Hawaiian plume: Osmium
... recycling of the lithospheric plate back into the Earth's mantle via subduction at convergent plate boundaries play a principle role in the generation of long-lived chemical and isotopic heterogeneities in the mantle. Ocean island basalts (or OIB) are thought to represent the surface expression of l ...
... recycling of the lithospheric plate back into the Earth's mantle via subduction at convergent plate boundaries play a principle role in the generation of long-lived chemical and isotopic heterogeneities in the mantle. Ocean island basalts (or OIB) are thought to represent the surface expression of l ...
Primary magmas and mantle temperatures
... led to the concept of a generalized mantle potential temperature (Tp) with Tp ≈ 1280°C (McKenzie & Bickle, 1988). The crust and lithosphere are interpreted as a thin boundary layer over the asthenosphere, which is inferred to have a potential temperature of 1280°C and adiabatic temperature distribut ...
... led to the concept of a generalized mantle potential temperature (Tp) with Tp ≈ 1280°C (McKenzie & Bickle, 1988). The crust and lithosphere are interpreted as a thin boundary layer over the asthenosphere, which is inferred to have a potential temperature of 1280°C and adiabatic temperature distribut ...
seamount subduction and earthquakes
... rupture history of large subduction zone earthquakes, the deep seismic structure of forearc overriding plates, and the morphology of subducting oceanic plates. Kodaira et al. (2000) used an integrated data set of earthquake aftershock relocations, seismic refraction, and swath bathymetry data to sug ...
... rupture history of large subduction zone earthquakes, the deep seismic structure of forearc overriding plates, and the morphology of subducting oceanic plates. Kodaira et al. (2000) used an integrated data set of earthquake aftershock relocations, seismic refraction, and swath bathymetry data to sug ...
Trace element evidence from seamounts for recycled oceanic crust
... Rise. These data indicate that the heterogeneous mantle source that supplies the seamounts consists of two components: Ž1. an extremely depleted component, much more depleted than estimates of the source of depleted MORB; and Ž2. an enriched component even more enriched than average OIB. The deplete ...
... Rise. These data indicate that the heterogeneous mantle source that supplies the seamounts consists of two components: Ž1. an extremely depleted component, much more depleted than estimates of the source of depleted MORB; and Ž2. an enriched component even more enriched than average OIB. The deplete ...
Can progressive melt extraction from a plum
... plume upwelling. These depleted leftovers are hot and buoyant so they pond beneath the lithosphere as an asthenosphere layer. When they rise and melt later on beneath a mid-ocean ridge, a depleted mid-ocean ridge basalt is extracted. The now extremely depleted leftovers, ~85% of the mass of the orig ...
... plume upwelling. These depleted leftovers are hot and buoyant so they pond beneath the lithosphere as an asthenosphere layer. When they rise and melt later on beneath a mid-ocean ridge, a depleted mid-ocean ridge basalt is extracted. The now extremely depleted leftovers, ~85% of the mass of the orig ...
The origin and occurrence of
... individual volcanoes on the Martian surface are large enough to be classed as LIPs (Montesi, 2000). Such as Olympus Mons which is the largest volcano in the solar system. It is also larger than the largest LIP known on Earth the OJP. (Zuber, 2005). Presently Mars is a single plate planet with no act ...
... individual volcanoes on the Martian surface are large enough to be classed as LIPs (Montesi, 2000). Such as Olympus Mons which is the largest volcano in the solar system. It is also larger than the largest LIP known on Earth the OJP. (Zuber, 2005). Presently Mars is a single plate planet with no act ...
Geology of Maui
... alkalic cap (most of the volcano’s modern surface) •is still in the postsheild alkalic cap stage •includes Haleakala crater - an erosional feature modified by later eruptions, Last erupted in 1790. ...
... alkalic cap (most of the volcano’s modern surface) •is still in the postsheild alkalic cap stage •includes Haleakala crater - an erosional feature modified by later eruptions, Last erupted in 1790. ...
Radiogenic isotope-3He/4He-δ18O relationships for global
... Sr/86Sr-ε143Nd-206Pb/204Pb compositions of high-3He/4He samples are constant at ...
... Sr/86Sr-ε143Nd-206Pb/204Pb compositions of high-3He/4He samples are constant at ...
Evidence for melting of garnet pyroxenite in the generation of
... wide. Spinel lherzolite xenoliths hosted within the Oahu post-erosional lavas have Os-isotopic compositions ( l S 7 0 s / 1 8 8 0 S = 0.124-0.130) typical of abyssal peridotites. Many of these lherzolites have been extensively metasomatized (e.g. Sen, et al., 1993), but this metasomatism has had ess ...
... wide. Spinel lherzolite xenoliths hosted within the Oahu post-erosional lavas have Os-isotopic compositions ( l S 7 0 s / 1 8 8 0 S = 0.124-0.130) typical of abyssal peridotites. Many of these lherzolites have been extensively metasomatized (e.g. Sen, et al., 1993), but this metasomatism has had ess ...
Earth and Planetary Science Letters
... for the bulk mantle, the model of Nizkous et al. (2006) for the uppermost mantle, and that of Shapiro et al. (2000) for the crust. We build a database of P-S conversion points beneath the central point of the three stations (lat: 160.63, lon: 55.96) relying on the TauP algorithm (Crotwell et al., 19 ...
... for the bulk mantle, the model of Nizkous et al. (2006) for the uppermost mantle, and that of Shapiro et al. (2000) for the crust. We build a database of P-S conversion points beneath the central point of the three stations (lat: 160.63, lon: 55.96) relying on the TauP algorithm (Crotwell et al., 19 ...
Deep Mantle Plumes and Geoscience Vision
... superstition and magic, but more importantly to a serious awe and reverence for the nighttime sky and a hunger for understanding Nature in all its variety. This spiritual hunger was a theme of Eldridge Moores in his address to you a year ago, and I carry on the theme. Einstein may have been a geolog ...
... superstition and magic, but more importantly to a serious awe and reverence for the nighttime sky and a hunger for understanding Nature in all its variety. This spiritual hunger was a theme of Eldridge Moores in his address to you a year ago, and I carry on the theme. Einstein may have been a geolog ...
mantle plumes and hot spots - The Centre for Earth Evolution and
... is underlain by a broad upwelling or that widespread flow from a plume is occurring beneath the lithosphere, with locations of volcanism controlled by lithospheric stresses. Geometry and radiometric age data of hotspot tracks indicate that the relative motion of hotspots is typically slow compared t ...
... is underlain by a broad upwelling or that widespread flow from a plume is occurring beneath the lithosphere, with locations of volcanism controlled by lithospheric stresses. Geometry and radiometric age data of hotspot tracks indicate that the relative motion of hotspots is typically slow compared t ...
Twin Hotspot Tracks and Ridge Jumps
... Udo Barckhausen Federal Institute for Geosciences and Natural Resources Germany ...
... Udo Barckhausen Federal Institute for Geosciences and Natural Resources Germany ...
The Yellowstone Hotspot: Plume or Not?
... arise from boundary layers (i.e., the core-mantle boundary), oceanic lithosphere is thinner and easier to penetrate than continental lithosphere, and upper mantle flow beneath the interior of large tectonic plates should be simpler than at plate boundaries. The mantle plume model therefore works wel ...
... arise from boundary layers (i.e., the core-mantle boundary), oceanic lithosphere is thinner and easier to penetrate than continental lithosphere, and upper mantle flow beneath the interior of large tectonic plates should be simpler than at plate boundaries. The mantle plume model therefore works wel ...
Activity 1 Where are the Volcanoes?
... its internal storehouse of energy. No single source of data tells the whole story, but a map is a great place to begin. On average, about 60 of Earth’s 550 historically active volcanoes erupt each year. Geologists have long known that volcanoes are abundant along the edges of certain continents.The ...
... its internal storehouse of energy. No single source of data tells the whole story, but a map is a great place to begin. On average, about 60 of Earth’s 550 historically active volcanoes erupt each year. Geologists have long known that volcanoes are abundant along the edges of certain continents.The ...
Sea-floor basement morphology: Distinguishing
... modulate the oceanic crust formed by seafloor spreading. (A thicker crust and off-axis volcanism are two features commonly attributed to hotspot modulation). Much has been learned about the thickness, structure and composition of the oceanic crust where the Mid-Oceanic Ridge axis passes over or near ...
... modulate the oceanic crust formed by seafloor spreading. (A thicker crust and off-axis volcanism are two features commonly attributed to hotspot modulation). Much has been learned about the thickness, structure and composition of the oceanic crust where the Mid-Oceanic Ridge axis passes over or near ...
lecture7_tomo
... Plumes are generally narrow, active structures that come from the “abyss” (English: relatively primitive mantle), but the ridge process is very shallow and are passive features due to decompression melting. They are really as different as “Yins” (ridge process) and “Yangs” (plumes). But could there ...
... Plumes are generally narrow, active structures that come from the “abyss” (English: relatively primitive mantle), but the ridge process is very shallow and are passive features due to decompression melting. They are really as different as “Yins” (ridge process) and “Yangs” (plumes). But could there ...
types of volcanoes
... Justification: It is extremely important for volcanologists to know what factors may cause an eruption. The presence of water, such as in a lake or an ocean may cause an eruption because water affects the buoyancy of magma in the earth’s crust. Hot spots pierce the earth’s crust like a blowtorch, cr ...
... Justification: It is extremely important for volcanologists to know what factors may cause an eruption. The presence of water, such as in a lake or an ocean may cause an eruption because water affects the buoyancy of magma in the earth’s crust. Hot spots pierce the earth’s crust like a blowtorch, cr ...
Hawaii hotspot
The Hawaii hotspot is a volcanic hotspot located near the namesake Hawaiian Islands, in the northern Pacific Ocean. One of the most well-known and heavily studied hotspots in the world, the Hawaii plume is responsible for the creation of the Hawaiian – Emperor seamount chain, an over 5,800 kilometres (3,600 mi) long chain of volcanoes, four of which are active, two of which are dormant, and more than 123 of which are extinct, many having since been ground beneath the waves by erosion as seamounts and atolls. The chain extends from south of the island of Hawaiʻi to the edge of the Aleutian Trench, near the eastern edge of Russia. While most volcanoes are created by geological activity at tectonic plate boundaries, the Hawaii hotspot is located far from plate boundaries. The classic hotspot theory, first proposed in 1963 by John Tuzo Wilson, proposes that a single, fixed mantle plume builds volcanoes that then, cut off from their source by the movement of the Pacific Plate, become increasingly inactive and eventually erode below sea level over millions of years. According to this theory, the nearly 60° bend where the Emperor and Hawaiian segments of the chain meet was caused by a sudden shift in the movement of the Pacific Plate. In 2003, fresh investigations of this irregularity led to the proposal of a mobile hotspot theory, suggesting that hotspots are mobile, not fixed, and that the 47-million-year-old bend was caused by a shift in the hotspot's motion rather than the plate's.Ancient Hawaiians were the first to recognize the increasing age and weathered state of the volcanoes to the north as they progressed on fishing expeditions along the islands. The volatile state of the Hawaiian volcanoes and their constant battle with the sea was a major element in Hawaiian mythology, embodied in Pele, the deity of volcanoes. After the arrival of Europeans on the island, in 1880-1881 James Dwight Dana directed the first formal geological study of the hotspot's volcanics, confirming the relationship long observed by the natives. 1912 marked the founding of the Hawaiian Volcano Observatory by volcanologist Thomas Jaggar, initiating continuous scientific observation of the islands. In the 1970s, a mapping project was initiated to gain more information about the complex geology of Hawaii's seafloor.The hotspot has since been tomographically imaged, showing it to be 500 to 600 km (310 to 370 mi) wide and up to 2,000 km (1,200 mi) deep, and olivine and garnet-based studies have shown its magma chamber is approximately 1,500 °C (2,730 °F). In its at least 85 million years of activity the hotspot has produced an estimated 750,000 km3 (180,000 cu mi) of rock. The chain's rate of drift has slowly increased over time, causing the amount of time each individual volcano is active to decrease, from 18 million years for the 76-million-year-old Detroit Seamount, to just under 900,000 for the one-million-year-old Kohala; on the other hand, eruptive volume has increased from 0.01 km3 (0.002 cu mi) per year to about 0.21 km3 (0.050 cu mi). Overall, this has caused a trend towards more active but quickly-silenced, closely spaced volcanoes—whereas volcanoes on the near side of the hotspot overlap each other (forming such superstructures as Hawaiʻi island and the ancient Maui Nui), the oldest of the Emperor seamounts are spaced as far as 200 km (120 mi) apart.