Seismic structures of the 154–160 Ma oceanic crust and uppermost... in the Northwest Pacific Basin
... We present detailed P-wave velocity models for the Northwest Pacific Basin which were produced in 154– 160 Ma at a high seafloor spreading half-rate of >8 cm/yr and have not been appreciably deformed by tectonic or igneous activity since then. We carried out wide-angle seismic experiments on two cro ...
... We present detailed P-wave velocity models for the Northwest Pacific Basin which were produced in 154– 160 Ma at a high seafloor spreading half-rate of >8 cm/yr and have not been appreciably deformed by tectonic or igneous activity since then. We carried out wide-angle seismic experiments on two cro ...
The Remarkable Diversity of Seafloor Vents
... A continually unfolding story As we develop these new techniques and instruments, our ability to explore ongoing seafloor processes will grow. More than a quarter-century into our studies, we still find ourselves constantly revising and refining our ideas about hydrothermal systems. At the same time ...
... A continually unfolding story As we develop these new techniques and instruments, our ability to explore ongoing seafloor processes will grow. More than a quarter-century into our studies, we still find ourselves constantly revising and refining our ideas about hydrothermal systems. At the same time ...
Mantle Reading
... the exhilarating feeling of digging into the wet sand with a plastic shovel. As the hole got bigger and deeper, you naturally wondered what would happen if you just kept digging and digging. How deep could you get? Would you really eventually pop up out of the ground somewhere in China, as your big ...
... the exhilarating feeling of digging into the wet sand with a plastic shovel. As the hole got bigger and deeper, you naturally wondered what would happen if you just kept digging and digging. How deep could you get? Would you really eventually pop up out of the ground somewhere in China, as your big ...
aircurrents - AIR Worldwide
... Very briefly, most earthquakes happen where two or more of the tectonic plates that make up the solid surface of the earth come together. These earthquakes are caused by the plates sliding against each other, butting into one another, or one plate slipping underneath another. The stresses and strain ...
... Very briefly, most earthquakes happen where two or more of the tectonic plates that make up the solid surface of the earth come together. These earthquakes are caused by the plates sliding against each other, butting into one another, or one plate slipping underneath another. The stresses and strain ...
Technical Abstract of the First Global Integrated Marine Assessment
... accordance with the programme of work for the period 2017-2020 for the second cycle of the Regular Process which was adopted by the Ad Hoc Working Group of the Whole on the Regular Process in August 2016 and endorsed by the General Assembly in December 2016. 2 This provides for, inter alia, support ...
... accordance with the programme of work for the period 2017-2020 for the second cycle of the Regular Process which was adopted by the Ad Hoc Working Group of the Whole on the Regular Process in August 2016 and endorsed by the General Assembly in December 2016. 2 This provides for, inter alia, support ...
The ocean-continent transition in the uniform lithospheric stretching
... level reached by new oceanic crust at mid-ocean ridge crests. However, it was proposed that stretching may occasionally exceed the value corresponding to 2.5 km subsidence, thus producing stretched continental crust that is deeper than the adjacent oceanic crust. As a result, a deep continental rnar ...
... level reached by new oceanic crust at mid-ocean ridge crests. However, it was proposed that stretching may occasionally exceed the value corresponding to 2.5 km subsidence, thus producing stretched continental crust that is deeper than the adjacent oceanic crust. As a result, a deep continental rnar ...
Chapter 17: Plate Tectonics
... In addition to making maps, scientists collected samples of deep-sea sediments and the underlying crust to try to better understand Earth’s ocean floors. Analysis of the rocks and sediments produced two important discoveries. First, the ages of the rocks that make up the seafloor vary in different p ...
... In addition to making maps, scientists collected samples of deep-sea sediments and the underlying crust to try to better understand Earth’s ocean floors. Analysis of the rocks and sediments produced two important discoveries. First, the ages of the rocks that make up the seafloor vary in different p ...
Magnetic Evidence for Seafloor Spreading
... Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. Scientists were sur ...
... Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. Scientists were sur ...
Moho Depth Estimation Using Gravitational Gradient Tensor (GGT
... Abstract: Investigating features of the continental crust and the upper mantle is an important goal in geophysical studies. In many cases, the Earth's crust is divided into two or three horizontal homogeneous layers but it is aimed to have a more detailed and meticulous view about crustal structure ...
... Abstract: Investigating features of the continental crust and the upper mantle is an important goal in geophysical studies. In many cases, the Earth's crust is divided into two or three horizontal homogeneous layers but it is aimed to have a more detailed and meticulous view about crustal structure ...
FINAL Review activity
... 21. Distinguish among the following types of consumers in terms of the food they eat and their position on the food chain, and give an example of a marine organism that would fit into each category including: A. herbivore B. carnivore C. omnivore ...
... 21. Distinguish among the following types of consumers in terms of the food they eat and their position on the food chain, and give an example of a marine organism that would fit into each category including: A. herbivore B. carnivore C. omnivore ...
Lecture #10 -- Magma types and types of eruptions (text pages 151
... high iron content. They have low viscosity because they are hot (>1000°C) and have low silica content and have low volatile (H2O) contents. Therefore they erupt passively as lava flows, forming spatter cones and flows, shield volcanoes (like in Hawaii -- see figure below) and large lava plateaus (li ...
... high iron content. They have low viscosity because they are hot (>1000°C) and have low silica content and have low volatile (H2O) contents. Therefore they erupt passively as lava flows, forming spatter cones and flows, shield volcanoes (like in Hawaii -- see figure below) and large lava plateaus (li ...
Divergent boundaries
... laser-electronic instruments. However, because plate motions are global in scale, they are best measured by satellite-based methods. The late 1970s witnessed the rapid growth of space geodesy, a term applied to space-based techniques for taking precise, repeated measurements of carefully chosen poin ...
... laser-electronic instruments. However, because plate motions are global in scale, they are best measured by satellite-based methods. The late 1970s witnessed the rapid growth of space geodesy, a term applied to space-based techniques for taking precise, repeated measurements of carefully chosen poin ...
Plate Boundaries
... in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior written permission of the publisher or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency Ltd, Saffron House, 6–10 Kirby Street, Lon ...
... in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior written permission of the publisher or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency Ltd, Saffron House, 6–10 Kirby Street, Lon ...
Front Matter - Assets - Cambridge University Press
... Roger Searle is Emeritus Professor of Geophysics at Durham University. He has spent 40 years studying mid-ocean ridges, and was a pioneer in the use of side-scan sonar to study their geodynamic, tectonic and volcanic processes. In his research he also uses topographic analysis and gravity and magnet ...
... Roger Searle is Emeritus Professor of Geophysics at Durham University. He has spent 40 years studying mid-ocean ridges, and was a pioneer in the use of side-scan sonar to study their geodynamic, tectonic and volcanic processes. In his research he also uses topographic analysis and gravity and magnet ...
Structure of the southern Jalisco subduction zone, Mexico, as
... colored fields are the densities in g/cm3 accepted for the model. Note that the maximum recorded depth of seismicity directly under the Barra de Navidad profile is around 80 km, while there are several deeper earthquakes in the southeastern part of the Jalisco subduction zone which are also shown on ...
... colored fields are the densities in g/cm3 accepted for the model. Note that the maximum recorded depth of seismicity directly under the Barra de Navidad profile is around 80 km, while there are several deeper earthquakes in the southeastern part of the Jalisco subduction zone which are also shown on ...
Plate Tectonics Lab II - Mercer Island School District
... Island-arc magmas, on the other hand, are not as contaminated because they pass only through oceanic crust (which is predominantly basaltic) on their way to the surface. Convergent plate-margin magmas in general are much richer in volatiles (e.g. gases such as water and carbon dioxide) than are the ...
... Island-arc magmas, on the other hand, are not as contaminated because they pass only through oceanic crust (which is predominantly basaltic) on their way to the surface. Convergent plate-margin magmas in general are much richer in volatiles (e.g. gases such as water and carbon dioxide) than are the ...
Features of Caucasian Segment of the Alpine
... present‐day) volcanism, which extends in submeridional (Transcaucasian) direction from the eastern Anatolia via the Lesser to the Greater Caucasus, where large Elbrus and Kazbek volcanoes occur. Volcanics of this belt on their petrological and geochemical features are often cl ...
... present‐day) volcanism, which extends in submeridional (Transcaucasian) direction from the eastern Anatolia via the Lesser to the Greater Caucasus, where large Elbrus and Kazbek volcanoes occur. Volcanics of this belt on their petrological and geochemical features are often cl ...
i13 Drift versus land bridges Mesosaurus > - e
... in the rock of the mantle. However, away from its source which is a hotspot, an aseismic ridge is progressively lowered as it is also part of the lithosphere that (for 60 million years) progressively thickens by cooling away from the ridge where it originates.9 Guyots are individual seamounts, built ...
... in the rock of the mantle. However, away from its source which is a hotspot, an aseismic ridge is progressively lowered as it is also part of the lithosphere that (for 60 million years) progressively thickens by cooling away from the ridge where it originates.9 Guyots are individual seamounts, built ...
10. Crustal Structure of the Japan Trench: The Effect of Subduction
... In terms of plate tectonics, the convergence of two crustal plates may result in underthrusting (subduction) of one plate beneath the other. The process generally envisioned for seismically active island arcs, marked by a deep-sea trench, is that the sediments on the descending oceanic plate are eit ...
... In terms of plate tectonics, the convergence of two crustal plates may result in underthrusting (subduction) of one plate beneath the other. The process generally envisioned for seismically active island arcs, marked by a deep-sea trench, is that the sediments on the descending oceanic plate are eit ...
Continents On The Move
... between the separating plates, some of it melts to form magma, due to decreasing pressure conditions rather than temperature change. Most of the magma rises to the Earth’s surface or the sea floor, where it cools to form new oceanic crust. So, a continuous and intense volcanism takes place along the ...
... between the separating plates, some of it melts to form magma, due to decreasing pressure conditions rather than temperature change. Most of the magma rises to the Earth’s surface or the sea floor, where it cools to form new oceanic crust. So, a continuous and intense volcanism takes place along the ...
Ecological values of the 12 miles zone of Bonaire
... allow photosynthesis. It is therefore also called the photic or sunlight zone. It extends from the surface to 200 meters. The part of this zone above the drop-off of the continental shelf is called the neritic zone, the part beyond the shelf break is the oceanic zone. ...
... allow photosynthesis. It is therefore also called the photic or sunlight zone. It extends from the surface to 200 meters. The part of this zone above the drop-off of the continental shelf is called the neritic zone, the part beyond the shelf break is the oceanic zone. ...
EENS 2120 Petrology Prof. Stephen A. Nelson Igneous Rocks of the
... Since Cpx would be the first solid phase to disappear during melting, further melting of peridotite at any of these pressure would produce liquids with compositions that lie along the Ol - Opx boundary curve at each pressure. Let's imagine that a liquid is produced at a pressure of 20 kb by partial ...
... Since Cpx would be the first solid phase to disappear during melting, further melting of peridotite at any of these pressure would produce liquids with compositions that lie along the Ol - Opx boundary curve at each pressure. Let's imagine that a liquid is produced at a pressure of 20 kb by partial ...
Mysteries of the mountains
... Philip England and Joseph Martinod (1993) suggested that sudden elevation, eight million years ago, of the already existing and vast Tibetan plateau to its current altitude of about 5,000 metres above sealevel, resulted in an intensification of the regional monsoon. Thereby, they also initiated a di ...
... Philip England and Joseph Martinod (1993) suggested that sudden elevation, eight million years ago, of the already existing and vast Tibetan plateau to its current altitude of about 5,000 metres above sealevel, resulted in an intensification of the regional monsoon. Thereby, they also initiated a di ...
Petrological nature of the oceanic Moho
... been defined by seismic nature. It has therefore importance as one of rare examples of collaboration between material geosciences (petrology or geology) and geophysics (seismology). Drilling through the oceanic Moho into the upper mantle is fundamentally important to in-situ observe the shallowest g ...
... been defined by seismic nature. It has therefore importance as one of rare examples of collaboration between material geosciences (petrology or geology) and geophysics (seismology). Drilling through the oceanic Moho into the upper mantle is fundamentally important to in-situ observe the shallowest g ...
Plate Tectonics Assignment(3-27-13)
... Click me for the animation Right Side: Ocean Convergent Boundary Situation 1: 1. Hit play in the animation and observe: (2 pts) Write down two observations as it applies to trench, volcanoes, subduction a. b. 2. Use the density tool at the bottom to find the density of the magma and the mantle aroun ...
... Click me for the animation Right Side: Ocean Convergent Boundary Situation 1: 1. Hit play in the animation and observe: (2 pts) Write down two observations as it applies to trench, volcanoes, subduction a. b. 2. Use the density tool at the bottom to find the density of the magma and the mantle aroun ...
Abyssal plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills). In addition to these elements, active oceanic basins (those that are associated with a moving plate tectonic boundary) also typically include an oceanic trench and a subduction zone.Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. The creation of the abyssal plain is the end result of spreading of the seafloor (plate tectonics) and melting of the lower oceanic crust. Magma rises from above the asthenosphere (a layer of the upper mantle) and as this basaltic material reaches the surface at mid-ocean ridges it forms new oceanic crust. This is constantly pulled sideways by spreading of the seafloor. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons down into deeper water. The remainder of the sediment is composed chiefly of pelagic sediments. Metallic nodules are common in some areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt, and copper. These nodules may provide a significant resource for future mining ventures.Owing in part to their vast size, abyssal plains are currently believed to be a major reservoir of biodiversity. The abyss also exerts significant influence upon ocean carbon cycling, dissolution of calcium carbonate, and atmospheric CO2 concentrations over timescales of 100–1000 years. The structure and function of abyssal ecosystems are strongly influenced by the rate of flux of food to the seafloor and the composition of the material that settles. Factors such as climate change, fishing practices, and ocean fertilization are expected to have a substantial effect on patterns of primary production in the euphotic zone. This will undoubtedly impact the flux of organic material to the abyss in a similar manner and thus have a profound effect on the structure, function and diversity of abyssal ecosystems.