Cascadia subduction slab heterogeneity revealed by three
... We highlight two features in this reflectivity model. First, the migration algorithm recovers the 410 km discontinuity approximately as a flat interface near 410 km depth. Second, east of 121°W longitude, a strong negative (blue) signal appears between 150 and 200 km depth. We identify this signal as ...
... We highlight two features in this reflectivity model. First, the migration algorithm recovers the 410 km discontinuity approximately as a flat interface near 410 km depth. Second, east of 121°W longitude, a strong negative (blue) signal appears between 150 and 200 km depth. We identify this signal as ...
Evolution of the Earth as an andesite planet: water, plate tectonics
... The presence of a high-temperature metallic core, common to all terrestrial planets (Fig. 1) (Aitta, 2012; Smith et al., 2012; Stevenson, 2001), causes convection in the mantle with a high Rayleigh number. Since mantle viscosity strongly depends on temperature (e.g., Karato and Wu, 1993), the top th ...
... The presence of a high-temperature metallic core, common to all terrestrial planets (Fig. 1) (Aitta, 2012; Smith et al., 2012; Stevenson, 2001), causes convection in the mantle with a high Rayleigh number. Since mantle viscosity strongly depends on temperature (e.g., Karato and Wu, 1993), the top th ...
Seismic structure of the northern end of the Ryukyu Trench... southeast of Kyushu, Japan
... the southwestern end of the profile. Only the region shallower than 5 km could be determined by the first arrival tomographic inversion. Because of very few first arrivals propagating in the deeper part with thick and low velocity, we mainly conducted forward modeling using later arrivals both of re ...
... the southwestern end of the profile. Only the region shallower than 5 km could be determined by the first arrival tomographic inversion. Because of very few first arrivals propagating in the deeper part with thick and low velocity, we mainly conducted forward modeling using later arrivals both of re ...
Concept 25.4: The rise and fall of dominant groups reflect
... • At three points in time, the land masses of Earth have formed a supercontinent: 1.1 billion, 600 million, and 250 million years ago • Earth’s continents move slowly over the underlying hot mantle through the process of continental drift • Oceanic and continental plates can collide, separate, or sl ...
... • At three points in time, the land masses of Earth have formed a supercontinent: 1.1 billion, 600 million, and 250 million years ago • Earth’s continents move slowly over the underlying hot mantle through the process of continental drift • Oceanic and continental plates can collide, separate, or sl ...
Investigating tectonic-erosion interactions
... structures, topography, precipitation, and exhumation rates as recorded by low-temperature thermochronology data all vary significantly from west to east. In particular, segments of the belt that are characterized by a clear topographic step between the Lesser and Higher Himalaya, associated with a ...
... structures, topography, precipitation, and exhumation rates as recorded by low-temperature thermochronology data all vary significantly from west to east. In particular, segments of the belt that are characterized by a clear topographic step between the Lesser and Higher Himalaya, associated with a ...
Earth Science 13.1 Precambrian Time
... Earth’s oceans formed as the planet continued to cool. The water vapor condensed to form clouds, and the great rains began. At first, the rainwater evaporated in the hot air before reaching the ...
... Earth’s oceans formed as the planet continued to cool. The water vapor condensed to form clouds, and the great rains began. At first, the rainwater evaporated in the hot air before reaching the ...
9-2 Section Summary
... spoon heats up in a hot pot of soup. The transfer of heat by the movement of a heated fluid is called convection. Fluids include liquids and gases. During convection, heated particles of a fluid begin to flow, transferring heat energy from one part of the fluid to another. Heat transfer by convectio ...
... spoon heats up in a hot pot of soup. The transfer of heat by the movement of a heated fluid is called convection. Fluids include liquids and gases. During convection, heated particles of a fluid begin to flow, transferring heat energy from one part of the fluid to another. Heat transfer by convectio ...
Paleomagnetic data from Early Cretaceous volcanic rocks of West
... nor tectonic rotations relative to the main Eurasia continent since the Cretaceous (tables 2 and 3). The same features are observed for Inner Mongolia from paleomagnetitic study on the tuff of Pingzhuang. The Korea block has no horizontal movement and rotation relative to Eurasia since the Tertiary[ ...
... nor tectonic rotations relative to the main Eurasia continent since the Cretaceous (tables 2 and 3). The same features are observed for Inner Mongolia from paleomagnetitic study on the tuff of Pingzhuang. The Korea block has no horizontal movement and rotation relative to Eurasia since the Tertiary[ ...
Key Question: 3
... 33. Oceans become deeper moving away from ridges due to: a. decreasing thickness of the lithosphere. b. increasing density of oceanic basalts. c. increases in sediment accumulations. d. polar wandering. e. thermal contraction of hot asthenosphere. Answer: E Key Question: 3 Skill: comprehension Diffi ...
... 33. Oceans become deeper moving away from ridges due to: a. decreasing thickness of the lithosphere. b. increasing density of oceanic basalts. c. increases in sediment accumulations. d. polar wandering. e. thermal contraction of hot asthenosphere. Answer: E Key Question: 3 Skill: comprehension Diffi ...
California Standards Grade Six Science Focus on Earth Science
... location of earthquakes, volcanoes, and mid-ocean ridges; and the distribution of fossils, rock types, and ancient climatic zones. □ know Earth is composed of several layers: a cold, brittle lithosphere; a hot, convection mantle; and a dense, metallic core. □ know lithospheric plates the size of con ...
... location of earthquakes, volcanoes, and mid-ocean ridges; and the distribution of fossils, rock types, and ancient climatic zones. □ know Earth is composed of several layers: a cold, brittle lithosphere; a hot, convection mantle; and a dense, metallic core. □ know lithospheric plates the size of con ...
Chapter 30: The Interior of the Earth
... strain at which they can bend no further, they rupture abruptly and then rebound somewhat like a rubber band that has just been pulled apart. The phenomenon is called “elastic rebound,” and it is illustrated in Figure 30.3. The break along which the failure of the lithosphere occurs is called a faul ...
... strain at which they can bend no further, they rupture abruptly and then rebound somewhat like a rubber band that has just been pulled apart. The phenomenon is called “elastic rebound,” and it is illustrated in Figure 30.3. The break along which the failure of the lithosphere occurs is called a faul ...
04 Earth`s Dynamic Surface
... Directions: Create a glossary for the terms listed below. Your glossary should include a definition and the part of speech for each term. The glossary entries should be in alphabetical order. The first term is done for you. ...
... Directions: Create a glossary for the terms listed below. Your glossary should include a definition and the part of speech for each term. The glossary entries should be in alphabetical order. The first term is done for you. ...
P-wave velocity structure in the central Japan Basin, Japan
... approximately 300 m in horizontal distance. To understand the shallow structure, the airgun signals were recorded by not only OBSs but also a single-channel hydrophone streamer towed from the R/V Professor Gagarinsky. The record section of OBS2 deployed on the central part of this survey line shows ...
... approximately 300 m in horizontal distance. To understand the shallow structure, the airgun signals were recorded by not only OBSs but also a single-channel hydrophone streamer towed from the R/V Professor Gagarinsky. The record section of OBS2 deployed on the central part of this survey line shows ...
The Earth`s Changing Surface
... Lithosphere - crust & upper mantle Asthenosphere - soft layer of mantle, like road tar Lower mantle - solid, hot rock ...
... Lithosphere - crust & upper mantle Asthenosphere - soft layer of mantle, like road tar Lower mantle - solid, hot rock ...
Basin Analysis
... Passive continental margins Thinning of continental crust during splitting of a continent Listric faults Graben facies Thermal subsidence of margin because of young oceanic lithosphere cooling Shallow sea to deep-water facies changes ...
... Passive continental margins Thinning of continental crust during splitting of a continent Listric faults Graben facies Thermal subsidence of margin because of young oceanic lithosphere cooling Shallow sea to deep-water facies changes ...
Genesis of Ultra-High Pressure Garnet Pyroxenite in Orogenic
... The major and trace element, and isotopic compositions of the studied Ronda and Beni Bousera UHP garnet pyroxenites lend support to the “Marble Cake Mantle” model [7] for the genesis of these pyroxenites. This model envisions the mantle source of oceanic basalts as a mélange of subducted, ancient oc ...
... The major and trace element, and isotopic compositions of the studied Ronda and Beni Bousera UHP garnet pyroxenites lend support to the “Marble Cake Mantle” model [7] for the genesis of these pyroxenites. This model envisions the mantle source of oceanic basalts as a mélange of subducted, ancient oc ...
Evolución tectono-magmatica de México central durante el Neogen
... A mantle plume to explain the TMVB? The model was essentially based on geochemistry and is inconsistent with the geology and tectonics of the TMVB. In their comment to the paper of Marquez et al. (1999) Ferrari & Rosas (1999) showed that: • neither the rifting nor the OIBs present the age progressio ...
... A mantle plume to explain the TMVB? The model was essentially based on geochemistry and is inconsistent with the geology and tectonics of the TMVB. In their comment to the paper of Marquez et al. (1999) Ferrari & Rosas (1999) showed that: • neither the rifting nor the OIBs present the age progressio ...
Earthquakes In Southwestern British Columbia
... California. The Juan de Fuca Plate is descending or subducting beneath the North American Plate at roughly the same rate as fingernails grow – about four centimetres per year. ...
... California. The Juan de Fuca Plate is descending or subducting beneath the North American Plate at roughly the same rate as fingernails grow – about four centimetres per year. ...
Restless Earth - DesignWorlds for Learning, Inc.
... Use a picture in the book of the island of Surtsey that began to form in the Atlantic Ocean near Iceland in 1963. Also talk about Hawaii and the new island that is forming. Use these examples to reinforce that the earth surface is constantly changing. Today, geologists divide the forces that change ...
... Use a picture in the book of the island of Surtsey that began to form in the Atlantic Ocean near Iceland in 1963. Also talk about Hawaii and the new island that is forming. Use these examples to reinforce that the earth surface is constantly changing. Today, geologists divide the forces that change ...
Volcanoes, molten magma, … and a nice cup of tea!
... waves slows down – the ‘low-velocity zone’ – which indicates that mantle rock (peridotite) is weaker in this area and so is capable of flowing like a viscous fluid, while still remaining in a solid state. This zone, the asthenosphere, is therefore weaker than the overlying more rigid part of the upp ...
... waves slows down – the ‘low-velocity zone’ – which indicates that mantle rock (peridotite) is weaker in this area and so is capable of flowing like a viscous fluid, while still remaining in a solid state. This zone, the asthenosphere, is therefore weaker than the overlying more rigid part of the upp ...
Eds. I. S. Evans, R. Dikau, E. Tokunaga, H. Ohmori... © by TERRAPUB, Tokyo, 2003.
... isostatic compensation that is on the border with astenosphere. It seems that both factors—high temperatures and dynamic prop of lithosphere plates are the result of an influence by anomalous mantle that generates intensive manifestation of magmatic processes on the ocean floor surface. Such phenome ...
... isostatic compensation that is on the border with astenosphere. It seems that both factors—high temperatures and dynamic prop of lithosphere plates are the result of an influence by anomalous mantle that generates intensive manifestation of magmatic processes on the ocean floor surface. Such phenome ...
Historical Geology Tectonics
... Suture zones usually have symmetrical patterns of rock types (folded sedimentary, metamorphic, granite) and the high rugged mountains resulting from orogenesis are subject to intense erosion, shedding sediment to both sides of the mountain range. ...
... Suture zones usually have symmetrical patterns of rock types (folded sedimentary, metamorphic, granite) and the high rugged mountains resulting from orogenesis are subject to intense erosion, shedding sediment to both sides of the mountain range. ...
Magnitude 7.8 SW OF SUMATRA, INDONESIA
... southern Sumatra, Indonesia, as a result of strike-slip faulting within the mantle lithosphere of the Indo-Australia Plate. There are currently no reports of damage or injury, and there is no risk of a large tsunami. ...
... southern Sumatra, Indonesia, as a result of strike-slip faulting within the mantle lithosphere of the Indo-Australia Plate. There are currently no reports of damage or injury, and there is no risk of a large tsunami. ...
Plate tectonics
Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός ""pertaining to building"") is a scientific theory that describes the large-scale motion of Earth's lithosphere. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. The geoscientific community accepted the theory after the concepts of seafloor spreading were later developed in the late 1950s and early 1960s.The lithosphere, which is the rigid outermost shell of a planet (on Earth, the crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight major plates (depending on how they are defined) and many minor plates. Where plates meet, their relative motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically varies from zero to 100 mm annually.Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some supporters) propose gradual shrinking (contraction) or gradual expansion of the globe.Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.