Volcanism in the Afar Rift sustained by decompression melting with
... Cynthia Ebinger4 , Ian D. Bastow3 , Atalay Ayele5 , Manahloh Belachew4,5 and Graham Stuart6 Continental breakup is caused by some combination of heating and stretching1,2 . The Afar Rift system in Africa is an example of active continental rifting, where a mantle plume probably weakened the lithosph ...
... Cynthia Ebinger4 , Ian D. Bastow3 , Atalay Ayele5 , Manahloh Belachew4,5 and Graham Stuart6 Continental breakup is caused by some combination of heating and stretching1,2 . The Afar Rift system in Africa is an example of active continental rifting, where a mantle plume probably weakened the lithosph ...
Today`s Quiz -
... Drummond H. Matthews of the University of Cambridge and a research student, Frederick J. Vine, postulated in 1963 that the new crust would have a magnetization aligned with the field at the time of its formation. If the magnetic field was normal, as it is today, the magnetization of the crust would ...
... Drummond H. Matthews of the University of Cambridge and a research student, Frederick J. Vine, postulated in 1963 that the new crust would have a magnetization aligned with the field at the time of its formation. If the magnetic field was normal, as it is today, the magnetization of the crust would ...
(2013) Porous fluid flow enables oceanic subduction initiation on
... zone formed atop of the slab maintains decoupling between the plates and the lubrication of the slab descending. This stage is accompanied by rapid trench rollback continuously accelerating with an average velocity of 16.3 cm/yr. As a result, the model evolves into a self-sustaining subduction (Figu ...
... zone formed atop of the slab maintains decoupling between the plates and the lubrication of the slab descending. This stage is accompanied by rapid trench rollback continuously accelerating with an average velocity of 16.3 cm/yr. As a result, the model evolves into a self-sustaining subduction (Figu ...
Seismicity and Earth`s Interior - North Coast Distance Education
... The magnitude of an earthquake is an objective measure of the amount of energy released. It is a much more precise measure than intensity. Earthquake magnitudes are based on direct measurements of the size (amplitude) of seismic waves, made with recording instruments, rather than on subjective obser ...
... The magnitude of an earthquake is an objective measure of the amount of energy released. It is a much more precise measure than intensity. Earthquake magnitudes are based on direct measurements of the size (amplitude) of seismic waves, made with recording instruments, rather than on subjective obser ...
The landslide
... mud extends away from the main slide. Field observations (Pedersen et al. 2001) indicate that this tongue formed due to gravity spreading of the avalanche as it settled on the alluvial fan. In the tail end depression of this tongue a small lake was formed, dammed by the toe of the slide (Fig. 4). Th ...
... mud extends away from the main slide. Field observations (Pedersen et al. 2001) indicate that this tongue formed due to gravity spreading of the avalanche as it settled on the alluvial fan. In the tail end depression of this tongue a small lake was formed, dammed by the toe of the slide (Fig. 4). Th ...
Extremely thin crust in the Indian Ocean possibly resulting from
... in the region further confirms this observation (Abercrombie et al. 2003; Engdahl et al. 2007). A recent bathymetry study near the subduction front shows similar deformation (Graindorge et al. 2008). Our study areas lies at the northern part of the Wharton Basin near the Sumatra subduction front (Fi ...
... in the region further confirms this observation (Abercrombie et al. 2003; Engdahl et al. 2007). A recent bathymetry study near the subduction front shows similar deformation (Graindorge et al. 2008). Our study areas lies at the northern part of the Wharton Basin near the Sumatra subduction front (Fi ...
How does Earth`s continental crust form? Scientists have
... Sampling the Earth's Crust crust. The new data suggests that for delamination to work would require removing much of the rock To determine how arc crust could turn into continental crust, Kelemen and Behn examined the from a 20-kilometer thickness of crust. However, only two known sites where a comp ...
... Sampling the Earth's Crust crust. The new data suggests that for delamination to work would require removing much of the rock To determine how arc crust could turn into continental crust, Kelemen and Behn examined the from a 20-kilometer thickness of crust. However, only two known sites where a comp ...
Evolution of the middle and lower crust during the transition from
... the least understood aspects of geodynamics. For example, what types of flow patterns evolve in the lower crust as tectonic settings and the driving forces of continental deformation change? How do flow patterns change as local rheologies and physical conditions in the deep crust change? What are th ...
... the least understood aspects of geodynamics. For example, what types of flow patterns evolve in the lower crust as tectonic settings and the driving forces of continental deformation change? How do flow patterns change as local rheologies and physical conditions in the deep crust change? What are th ...
Faulting and hydration of the Juan de Fuca plate system
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
Page 1 Ordovician orogeny in the Alps – a reappraisal Roger
... tectonics, and, conclusively, interpret the Ordovician magmatism as an atectonic thermal event with totally different implications for the Ordovician setting. On the other hand, new age data of Franz and Romer (2007) confirm that accretion, eclogitization, anatexis and pre- to synmagmatic deformatio ...
... tectonics, and, conclusively, interpret the Ordovician magmatism as an atectonic thermal event with totally different implications for the Ordovician setting. On the other hand, new age data of Franz and Romer (2007) confirm that accretion, eclogitization, anatexis and pre- to synmagmatic deformatio ...
On the origin of El Chichón volcano and subduction of
... 12 Ma. It has been proposed that TR represents a major transpressional structure formed along a former transform fault on the Guadalupe plate 15–20 Ma ago and the northern boundary of a microplate embedded into the Cocos Plate (Manea et al., 2005). Another important characteristic that makes TR dist ...
... 12 Ma. It has been proposed that TR represents a major transpressional structure formed along a former transform fault on the Guadalupe plate 15–20 Ma ago and the northern boundary of a microplate embedded into the Cocos Plate (Manea et al., 2005). Another important characteristic that makes TR dist ...
Gernigon, L., O. Olesen, J. Ebbing, S. Wienecke
... of the survey lines after smoothing of the polynomial fitted mis-lines, by means of a spline algorithm, to avoid unwanted distortion of the anomalies (e.g. Mauring et al., 2002). The International Geomagnetic Reference Field (IGRF-2005) was then subtracted from the levelled survey lines to produce th ...
... of the survey lines after smoothing of the polynomial fitted mis-lines, by means of a spline algorithm, to avoid unwanted distortion of the anomalies (e.g. Mauring et al., 2002). The International Geomagnetic Reference Field (IGRF-2005) was then subtracted from the levelled survey lines to produce th ...
New insights into the subducting oceanic crust in the Middle
... fabrics. Profile 106 crosses the trench where the oceanic crust is lacking a sedimentary cover. The high-amplitude arcuate event located at CDP 4100 (inset Fig. 4B) is indicative of a sharp geological feature within the subducting oceanic plate. This strong diffraction pattern is probably the result ...
... fabrics. Profile 106 crosses the trench where the oceanic crust is lacking a sedimentary cover. The high-amplitude arcuate event located at CDP 4100 (inset Fig. 4B) is indicative of a sharp geological feature within the subducting oceanic plate. This strong diffraction pattern is probably the result ...
california state university, northridge rayleigh wave tomography
... divides the North American plate and the Pacific plate. This tectonic system was formed during the Miocene period with the subduction of the Farallon plate and the East Pacific Rise (EPR) beneath California. The Farallon plate was subducting steadily beneath the North American plate from 37 to 30 Ma ...
... divides the North American plate and the Pacific plate. This tectonic system was formed during the Miocene period with the subduction of the Farallon plate and the East Pacific Rise (EPR) beneath California. The Farallon plate was subducting steadily beneath the North American plate from 37 to 30 Ma ...
Scientific Ocean Drilling of Mid-Ocean Ridge and Ridge
... processes, the seawater-crust chemical exchange and heat flux, and the diversity of subseafloor microbiology. The remainder of the morning of Day 1 was devoted to talks on the engineering and technology of ocean crustal drilling, including an overview of the history of DSDP/ODP/IODP projects, new te ...
... processes, the seawater-crust chemical exchange and heat flux, and the diversity of subseafloor microbiology. The remainder of the morning of Day 1 was devoted to talks on the engineering and technology of ocean crustal drilling, including an overview of the history of DSDP/ODP/IODP projects, new te ...
Granitoids
... A few broad generalizations: 1) Most granitoids of significant volume occur in areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may postdate the thickening event by tens of millions of years. Ima ...
... A few broad generalizations: 1) Most granitoids of significant volume occur in areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may postdate the thickening event by tens of millions of years. Ima ...
The Science of Tsunamis
... and, by plotting seismic activity, their boundaries have been defined (above).4 Tectonic plates are constantly diverging, converging or transforming. In divergent zones, the plates move away from each other, allowing basaltic magma to ooze to the seafloor and create the dense oceanic crust at midoce ...
... and, by plotting seismic activity, their boundaries have been defined (above).4 Tectonic plates are constantly diverging, converging or transforming. In divergent zones, the plates move away from each other, allowing basaltic magma to ooze to the seafloor and create the dense oceanic crust at midoce ...
The Moho in subduction zones - Earth and Space Sciences at the
... and second with the overriding plate. The seismic expression of both forms is linked to the nature of a landward dipping, low-velocity zone (LVZ) that has been detected in a majority of subduction zones about the globe and that approximately coincides with Wadati–Benioff seismicity. We review seismi ...
... and second with the overriding plate. The seismic expression of both forms is linked to the nature of a landward dipping, low-velocity zone (LVZ) that has been detected in a majority of subduction zones about the globe and that approximately coincides with Wadati–Benioff seismicity. We review seismi ...
Diamonds in Ophiolites
... at shallow depths in the upper mantle (cf. Yamamoto et al. 2013). One very important aspect of this model is that podiform chromitites in ophiolites may not always originate at shallow depths in the uppermost mantle, as widely thought. The chromitite formation may initially begin within or near the ...
... at shallow depths in the upper mantle (cf. Yamamoto et al. 2013). One very important aspect of this model is that podiform chromitites in ophiolites may not always originate at shallow depths in the uppermost mantle, as widely thought. The chromitite formation may initially begin within or near the ...
Decoupling along plate boundaries: Key variable controlling the
... the formation of two-sided orogens, with largescale folding being the dominant deformation mechanism (our experiment A). IMPLICATIONS FOR THE EVOLUTION OF COLLISIONAL MOUNTAIN BELTS AND THEIR FORELANDS The models discussed in this study represent end-member scenarios with constant mechanical boundar ...
... the formation of two-sided orogens, with largescale folding being the dominant deformation mechanism (our experiment A). IMPLICATIONS FOR THE EVOLUTION OF COLLISIONAL MOUNTAIN BELTS AND THEIR FORELANDS The models discussed in this study represent end-member scenarios with constant mechanical boundar ...
Geological Society, London, Special Publications
... 45 ~to the strike of the seafloor fabric to optimize the use of the side-scan sonar. Navigation consisted of GPS fixes for about 10 hours per day, and a combination of Transit satellites and dead reckoning when GPS was not available. ...
... 45 ~to the strike of the seafloor fabric to optimize the use of the side-scan sonar. Navigation consisted of GPS fixes for about 10 hours per day, and a combination of Transit satellites and dead reckoning when GPS was not available. ...
Subduction-driven recycling of continental margin lithosphere
... Receiver function images show the top of the Alboran slab merging with the Rif Moho at ,50–55 km depth, evidence that the descending Alboran plate is attached to the Rif lithosphere at the Moho. Under southern Iberia the Alboran slab lies close to the base of the Betic crust on an east–west axis. He ...
... Receiver function images show the top of the Alboran slab merging with the Rif Moho at ,50–55 km depth, evidence that the descending Alboran plate is attached to the Rif lithosphere at the Moho. Under southern Iberia the Alboran slab lies close to the base of the Betic crust on an east–west axis. He ...
Crustal structure of the ocean-island arc transition at the mid... (Bonin) arc margin Azusa Nishizawa , Kentaro Kaneda
... in the western part of OBS 213. PmP signals from the Moho of the island arc crust are also observed at some OBSs. PmP arrivals around +60 km in Fig. 2(a) can be explained within an error of 0.3 s, but PmP signals in the western part of OBS 213 are not clear. This may be due to lateral inhomogeneity ...
... in the western part of OBS 213. PmP signals from the Moho of the island arc crust are also observed at some OBSs. PmP arrivals around +60 km in Fig. 2(a) can be explained within an error of 0.3 s, but PmP signals in the western part of OBS 213 are not clear. This may be due to lateral inhomogeneity ...
Petrological nature of the oceanic Moho
... Nature of the Moho has been controversial for a long time; an isochemical phase transition boundary between gabbro (crust) and eclogite (mantle) was favored for the Moho by some people while a chemical boundary between mafic rocks (crust) and peridotitic rocks (upper mantle) is now favored by a majo ...
... Nature of the Moho has been controversial for a long time; an isochemical phase transition boundary between gabbro (crust) and eclogite (mantle) was favored for the Moho by some people while a chemical boundary between mafic rocks (crust) and peridotitic rocks (upper mantle) is now favored by a majo ...
