Lecture 13-15 Notes: Plate Tectonics
... o [We can now image at least the first stage of oceanic crust being recycled, using seismic tomography: old cold dense higher moduli faster wave speed] [PPT: Zhao et al. 1997 Tonga trench] During the mid-1960s, these observations led geologists to outline the main principles of plate tectoni ...
... o [We can now image at least the first stage of oceanic crust being recycled, using seismic tomography: old cold dense higher moduli faster wave speed] [PPT: Zhao et al. 1997 Tonga trench] During the mid-1960s, these observations led geologists to outline the main principles of plate tectoni ...
Geology of Oceanography
... The Theory of Seafloor Spreading • In the 1960’s geologists Harry Hess and Robert Dietz hypothesize that the seafloor is in a constant state of creation and destruction • New crust emerges as magma from the asthenosphere pushes up through the rift and solidifies into new crust. This new crust pushe ...
... The Theory of Seafloor Spreading • In the 1960’s geologists Harry Hess and Robert Dietz hypothesize that the seafloor is in a constant state of creation and destruction • New crust emerges as magma from the asthenosphere pushes up through the rift and solidifies into new crust. This new crust pushe ...
introduction to plate tectonics
... If the continents are arranged according to Wegener’s Pangaea reconstruction, glaciation in the southern hemisphere is confined to a much smaller area, and the absence of widespread glaciation in the northern hemisphere is more easily explained. ...
... If the continents are arranged according to Wegener’s Pangaea reconstruction, glaciation in the southern hemisphere is confined to a much smaller area, and the absence of widespread glaciation in the northern hemisphere is more easily explained. ...
Composition Once upon a time, billions of years ago
... core, heating up and becoming less dense as it goes. Once it gets hot enough, it begins to rise again. This process continually repeats itself, although one complete cycle takes millions of years to complete. Think of convection currents as a huge lava lamp. When rising current comes at a weaker par ...
... core, heating up and becoming less dense as it goes. Once it gets hot enough, it begins to rise again. This process continually repeats itself, although one complete cycle takes millions of years to complete. Think of convection currents as a huge lava lamp. When rising current comes at a weaker par ...
Earth Communication
... American continent. In Hess' model, convection currents push the ocean floor from the mid-ocean ridge to the trench where it is destroyed. The convection currents might also help move the continents, much like a conveyor belt. As Hess formulated his hypothesis, Robert Dietz independently proposed a ...
... American continent. In Hess' model, convection currents push the ocean floor from the mid-ocean ridge to the trench where it is destroyed. The convection currents might also help move the continents, much like a conveyor belt. As Hess formulated his hypothesis, Robert Dietz independently proposed a ...
Do Now - North Thurston Public Schools
... • There are several other volcanoes that are not created near a plate boundary but instead in the middle of a plate • They are created when a mantle plume is super heated by the core and burns through the crust building a volcano • In the case of an oceanic hotspot, the plate continues to move and t ...
... • There are several other volcanoes that are not created near a plate boundary but instead in the middle of a plate • They are created when a mantle plume is super heated by the core and burns through the crust building a volcano • In the case of an oceanic hotspot, the plate continues to move and t ...
Earth Communication
... American continent. In Hess' model, convection currents push the ocean floor from the mid-ocean ridge to the trench where it is destroyed. The convection currents might also help move the continents, much like a conveyor belt. As Hess formulated his hypothesis, Robert Dietz independently proposed a ...
... American continent. In Hess' model, convection currents push the ocean floor from the mid-ocean ridge to the trench where it is destroyed. The convection currents might also help move the continents, much like a conveyor belt. As Hess formulated his hypothesis, Robert Dietz independently proposed a ...
Lec5 - nptel
... Consider, for example, the tectonic environment in the vicinity of a spreading ridge plate boundary. First the crust is thin; hence the volume of rock in which strain energy can build up is small. Second, the horizontal component of the relative plate movement is extensional; hence the normal stress ...
... Consider, for example, the tectonic environment in the vicinity of a spreading ridge plate boundary. First the crust is thin; hence the volume of rock in which strain energy can build up is small. Second, the horizontal component of the relative plate movement is extensional; hence the normal stress ...
Plate Tectonics
... (4) sliding past each other The motion of the convection currents in the mantle beneath the Atlantic Ocean appears to be mainly making this ocean basin (1) deeper (3) wider (2) shallower (4) narrower ...
... (4) sliding past each other The motion of the convection currents in the mantle beneath the Atlantic Ocean appears to be mainly making this ocean basin (1) deeper (3) wider (2) shallower (4) narrower ...
The Theory of Continental Drift
... they found that the ocean floor had: – oceanic ridges - submerged mountain ranges ...
... they found that the ocean floor had: – oceanic ridges - submerged mountain ranges ...
pdf - University of Colorado Boulder
... Counterintuitively, they are also the site of volcanism. The melting of rocks in Earth’s interior that is required for this volcanism is thought to result from the entry of hydrous fluids into the hot overlying mantle from the descending oceanic crust4–6. North of the junction lie volcanoes that are ...
... Counterintuitively, they are also the site of volcanism. The melting of rocks in Earth’s interior that is required for this volcanism is thought to result from the entry of hydrous fluids into the hot overlying mantle from the descending oceanic crust4–6. North of the junction lie volcanoes that are ...
Pre-earthquake signals – Part II: Flow of battery currents in the crust
... observed and tentatively correlated with earthquake activity. The build-up of a positive ground potential seems to be consistent with most observations, including changes in the Total Electron Content, though the release of radon from the ground has been discussed as an alternative process (e.g. Hay ...
... observed and tentatively correlated with earthquake activity. The build-up of a positive ground potential seems to be consistent with most observations, including changes in the Total Electron Content, though the release of radon from the ground has been discussed as an alternative process (e.g. Hay ...
PEUXENOS
... the continent-al lithosphere in that part of the world, which in turn explains its high topography. ...
... the continent-al lithosphere in that part of the world, which in turn explains its high topography. ...
Tectonic Earthquakes of the Pacific Northwest The Pacific Northwest
... rotate much of western Oregon and Washington slowly about a pivot point in northeast Oregon.: Unwinding sixteen million years lets us SEE the permanent deformation caused by this rotation. The resulting deformation has broken the crust by normal, strike-slip, and thrust faults with motion histories ...
... rotate much of western Oregon and Washington slowly about a pivot point in northeast Oregon.: Unwinding sixteen million years lets us SEE the permanent deformation caused by this rotation. The resulting deformation has broken the crust by normal, strike-slip, and thrust faults with motion histories ...
Plate_Tectonics_Pangea_PowerPoint
... • Rock Types and Structures - Rock evidence for continental exists in the form of several mountain belts that end at one coastline, only to reappear on a landmass across the ocean. • Ancient Climates ...
... • Rock Types and Structures - Rock evidence for continental exists in the form of several mountain belts that end at one coastline, only to reappear on a landmass across the ocean. • Ancient Climates ...
CHAPTER 1 THE TECTONIC CYCLE
... 2. What is the main idea of this theory? 3. What causes the plates of the earth to move? 4. What causes magma to move in the mantle? 5. What was Pangea? 6. What proof do we have that the continents of the earth were once all ...
... 2. What is the main idea of this theory? 3. What causes the plates of the earth to move? 4. What causes magma to move in the mantle? 5. What was Pangea? 6. What proof do we have that the continents of the earth were once all ...
supplementary information
... background shows temperature at 220 km depth, while color contours denotes isotherms of temperatures 60 °C lower than the ambient mantle at different depths. The grey area (tracer distribution) indicates the thickest part (core) of the Shatsky conjugate plateau. A secondary grey area along north Mex ...
... background shows temperature at 220 km depth, while color contours denotes isotherms of temperatures 60 °C lower than the ambient mantle at different depths. The grey area (tracer distribution) indicates the thickest part (core) of the Shatsky conjugate plateau. A secondary grey area along north Mex ...
Do mantle plumes exist?
... extension. The mantle is fertilised by eclogite from subducted slabs, which becomes trapped in the mantle wedge (behind subduction zones) and the continental lithosphere. Cordery et al (1997) pointed out that the solidus and liquidus of eclogite in the trapped slab is lower than mantle peridotite wi ...
... extension. The mantle is fertilised by eclogite from subducted slabs, which becomes trapped in the mantle wedge (behind subduction zones) and the continental lithosphere. Cordery et al (1997) pointed out that the solidus and liquidus of eclogite in the trapped slab is lower than mantle peridotite wi ...
TennMaps_PlateTectonics
... The U.S. Navy found it the hard way in 1985 with the aircraft carrier Enterprise ...
... The U.S. Navy found it the hard way in 1985 with the aircraft carrier Enterprise ...
Chapter 2 Lower-crustal strength under the Dead Sea basin from
... was also used to relocate earthquakes. In each of the three structural units of Figure 2.4a, a one-dimensional velocity model was defined. The boundaries between the three units were derived from the maximum gradient of gravity (ten Brink et al., 1993). All three models are rather similar below the ...
... was also used to relocate earthquakes. In each of the three structural units of Figure 2.4a, a one-dimensional velocity model was defined. The boundaries between the three units were derived from the maximum gradient of gravity (ten Brink et al., 1993). All three models are rather similar below the ...
Part 3
... The coast of Nordland is known as an area where earthquake activity occurs from time to time. The biggest earthquake, about 6 on the Richter scale, occurred in the Rana area in 1819. In recent years, several registrations have been made which indicate that in some areas at least, land uplift is not ...
... The coast of Nordland is known as an area where earthquake activity occurs from time to time. The biggest earthquake, about 6 on the Richter scale, occurred in the Rana area in 1819. In recent years, several registrations have been made which indicate that in some areas at least, land uplift is not ...
An inventory and topographic analysis of glaciers in the Torngat
... overall negative mass balance for three of the four glaciers (Rogerson, 1986), and the importance of snowfall accumulation in local glacier mass balance and glacier debris cover for surface melt rates (Rogerson and others, 1986a). The mass-balance records support areal changes on ten glaciers betwee ...
... overall negative mass balance for three of the four glaciers (Rogerson, 1986), and the importance of snowfall accumulation in local glacier mass balance and glacier debris cover for surface melt rates (Rogerson and others, 1986a). The mass-balance records support areal changes on ten glaciers betwee ...
Plate boundaries: What landforms happen where?
... new crust to be formed. Small volcanoes can also be formed. As the 2 plates meet, the ocean plate sinks under the continental plate because it is denser. The oceanic plate melts, and composite volcanoes are formed along the margin. Earthquakes can also occur here because the 2 plates are clashing. A ...
... new crust to be formed. Small volcanoes can also be formed. As the 2 plates meet, the ocean plate sinks under the continental plate because it is denser. The oceanic plate melts, and composite volcanoes are formed along the margin. Earthquakes can also occur here because the 2 plates are clashing. A ...
Post-glacial rebound
Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.