Changing Earth
... As Africa moved toward southern Europe, the Mediterranean was confined (and became more salty). The Red Sea opened as a result of the rift system that is apparently continuous with the Great Rift Valley. This may eventually open a inland seaway through eastern Africa. ...
... As Africa moved toward southern Europe, the Mediterranean was confined (and became more salty). The Red Sea opened as a result of the rift system that is apparently continuous with the Great Rift Valley. This may eventually open a inland seaway through eastern Africa. ...
8.3 PowerPoint
... moved apart. Continental drift - d 3. Theory that Earth’s lithosphere is made up of huge, moving plates that are carried around the planet by motions in the mantle. Plate tectonics - b ...
... moved apart. Continental drift - d 3. Theory that Earth’s lithosphere is made up of huge, moving plates that are carried around the planet by motions in the mantle. Plate tectonics - b ...
Plate Tectonics
... • Throughout the earth’s history, the magnetic field has reversed itself many times. • Such reversals have come at irregular intervals, averaging about every 300,000 years; the last one was 780,000 years ago. Are ...
... • Throughout the earth’s history, the magnetic field has reversed itself many times. • Such reversals have come at irregular intervals, averaging about every 300,000 years; the last one was 780,000 years ago. Are ...
abstract
... earthquake events in 2002 and 2007. The findings for the 2002 Boso slow earthquake are as follows. (1) There are some interesting signals whish seem to originate from the fluid flow under the ground taking account of the polarity of .magnetic field components. (2) The characteristics of the observed ...
... earthquake events in 2002 and 2007. The findings for the 2002 Boso slow earthquake are as follows. (1) There are some interesting signals whish seem to originate from the fluid flow under the ground taking account of the polarity of .magnetic field components. (2) The characteristics of the observed ...
Chapter 2
... direction every few million years. Many rocks contain tiny magnetic particles & these move in molten rock. When the rock solidifies the particles freeze in their orientation ...
... direction every few million years. Many rocks contain tiny magnetic particles & these move in molten rock. When the rock solidifies the particles freeze in their orientation ...
SEA FLOOR SPREADING Mid
... •Proposed the seafloor spreading theory in 1962. •The Sea floor spreading theory states that new ocean crust is being created at mid-ocean ridges and destroyed at deep-sea trenches.. ...
... •Proposed the seafloor spreading theory in 1962. •The Sea floor spreading theory states that new ocean crust is being created at mid-ocean ridges and destroyed at deep-sea trenches.. ...
G2S15Lesson8 Tectoni..
... At various times in the past the orientation has been reversed. A rock crystallizing at this time would have a magnetism pointed toward the south magnetic pole. The magnetic time scale below provides a record of when the Earth’s magnetic field was either normal (black bars) or reversed (white bars). ...
... At various times in the past the orientation has been reversed. A rock crystallizing at this time would have a magnetism pointed toward the south magnetic pole. The magnetic time scale below provides a record of when the Earth’s magnetic field was either normal (black bars) or reversed (white bars). ...
Chapter 5-Study Questions
... ___13. Sea floor spreading is the mechanism responsible for producing ocean-floor material at the crest of oceanic ridges. ___14. The region where an oceanic slab sinks into the athenosphere because of convergence is called a subduction zone. ___15. When rocks exhibit the same magnetism as the prese ...
... ___13. Sea floor spreading is the mechanism responsible for producing ocean-floor material at the crest of oceanic ridges. ___14. The region where an oceanic slab sinks into the athenosphere because of convergence is called a subduction zone. ___15. When rocks exhibit the same magnetism as the prese ...
John Verhoogen - National Academy of Sciences
... Initially Verhoogen favored the self-reversal interpretation. However, Allan Cox in particular, after analyzing hundreds of volcanic samples from the Snake River Plain and elsewhere, found coherent reversal patterns that seemed could be rationalized only by having the geomagnetic field itself revers ...
... Initially Verhoogen favored the self-reversal interpretation. However, Allan Cox in particular, after analyzing hundreds of volcanic samples from the Snake River Plain and elsewhere, found coherent reversal patterns that seemed could be rationalized only by having the geomagnetic field itself revers ...
ES Unit 3 standards - Springfield Public Schools
... tectonic plates. Explain the factors that determine the type of volcanic ...
... tectonic plates. Explain the factors that determine the type of volcanic ...
Geology 208 History of Earth System Midterm Topics 1 Topics
... Mechanisms for raising sea level and rates of sea level rise Transgressive – Regressive sequences and Sloss Foreland basin and clastic wedge (flysch and molasse) Cyclothems Relative Age Principles of relative age dating and block diagram The nature of unconformities – what is implied F ...
... Mechanisms for raising sea level and rates of sea level rise Transgressive – Regressive sequences and Sloss Foreland basin and clastic wedge (flysch and molasse) Cyclothems Relative Age Principles of relative age dating and block diagram The nature of unconformities – what is implied F ...
Document
... Plates consist of crust and lithospheric mantle Any individual plate contains oceanic and/or continental crust Each plate relatively rigid, little internal deformation Plate boundaries defined by active seismic and volcanic activity Dynamic: new ones form, boundaries change character, etc. ...
... Plates consist of crust and lithospheric mantle Any individual plate contains oceanic and/or continental crust Each plate relatively rigid, little internal deformation Plate boundaries defined by active seismic and volcanic activity Dynamic: new ones form, boundaries change character, etc. ...
Lauren Winner G355 Lab Write-up May 18, 2010 Laboratory Title
... Basaltic lavas contain iron-bearing minerals such as magnetite which act like compasses. That is, as these iron-rich minerals cool below their Curie point, they become magnetized in the direction of the surrounding magnetic field. Studies of ancient magnetism (paleomagnetism) recorded in rocks of di ...
... Basaltic lavas contain iron-bearing minerals such as magnetite which act like compasses. That is, as these iron-rich minerals cool below their Curie point, they become magnetized in the direction of the surrounding magnetic field. Studies of ancient magnetism (paleomagnetism) recorded in rocks of di ...
Plate Tectonic Objectives
... 6. Know the main features of the seafloor and the relative age of rocks found at those locations. 7. Understand and explain why magnetic reversals provide the evidence Alfred Wegener was missing and how evidence of these reversals are found on the seafloor. 8. Define the theory of plate tectonics an ...
... 6. Know the main features of the seafloor and the relative age of rocks found at those locations. 7. Understand and explain why magnetic reversals provide the evidence Alfred Wegener was missing and how evidence of these reversals are found on the seafloor. 8. Define the theory of plate tectonics an ...
formation of Plate tectonic theory
... The discovery that some minerals can become magnetized parallel to the Earth's magnetic field was made in the nineteenth century. Early in the twentieth century, Bernard Brunhes made the startling discovery that some rocks are magnetized in the opposite orientation to the Earth's present-day magneti ...
... The discovery that some minerals can become magnetized parallel to the Earth's magnetic field was made in the nineteenth century. Early in the twentieth century, Bernard Brunhes made the startling discovery that some rocks are magnetized in the opposite orientation to the Earth's present-day magneti ...
Geological History
... • Isostasy- The crust floats on the mantle since the crust is less dense. • The heavier the crust, the more it will push on the mantle • Mantle is not “liquid” like we think of it…it has plasticity. ...
... • Isostasy- The crust floats on the mantle since the crust is less dense. • The heavier the crust, the more it will push on the mantle • Mantle is not “liquid” like we think of it…it has plasticity. ...
Plate Tectonics 1
... • Currently, the Pacific Ocean basin is shrinking as other ocean basins expand. • Seismicity is the frequency, magnitude and distribution of earthquakes. Earthquakes are concentrated along oceanic ridges, transform faults, trenches and island arcs. • Tectonism refers to the deformation of Earth’s cr ...
... • Currently, the Pacific Ocean basin is shrinking as other ocean basins expand. • Seismicity is the frequency, magnitude and distribution of earthquakes. Earthquakes are concentrated along oceanic ridges, transform faults, trenches and island arcs. • Tectonism refers to the deformation of Earth’s cr ...
presentation source
... • Strength of the field is greatest at the poles. • Source of Magnetic Field: – Earth’s magnetic field is generated in the liquid outer core by convection currents. – Convection of metal generates an electrical current that creates magnetic field. ...
... • Strength of the field is greatest at the poles. • Source of Magnetic Field: – Earth’s magnetic field is generated in the liquid outer core by convection currents. – Convection of metal generates an electrical current that creates magnetic field. ...
Shortly after the Earth formed, heat released by colliding particles
... • Age of rocks: – The farther you are away from the spreading center the older the age of the rock ...
... • Age of rocks: – The farther you are away from the spreading center the older the age of the rock ...
vgp302
... 90% of the modern geomagnetic field is represented by a simple dipole at the center of the earth. The remaining 10%, the “non-dipole” components, have a more complicated spatial structure. Geomagneticians assume that in the past the earth’s field was also dominated by the dipole component. We can de ...
... 90% of the modern geomagnetic field is represented by a simple dipole at the center of the earth. The remaining 10%, the “non-dipole” components, have a more complicated spatial structure. Geomagneticians assume that in the past the earth’s field was also dominated by the dipole component. We can de ...
Warm- Up
... under the other and what is the name for this process? 10. How much water is believed to be in the mantle? ...
... under the other and what is the name for this process? 10. How much water is believed to be in the mantle? ...
Earth Science Chapter 17: Plate Tectonics
... 300 million years old on several continents led Wegener to propose that these landmasses might have once been joined and covered with ice. The extent of the ice is shown in white. ...
... 300 million years old on several continents led Wegener to propose that these landmasses might have once been joined and covered with ice. The extent of the ice is shown in white. ...
Ch. 8 Vocab Study Guide
... 3. The switch in the Earth’s magnetic field is called: _______________________________________ 4. A solid sphere of metal at the Earth’s center: _________________________________ 5. This deep valley is formed as tectonic plates move apart and is found along a mid-ocean ridge: _______________________ ...
... 3. The switch in the Earth’s magnetic field is called: _______________________________________ 4. A solid sphere of metal at the Earth’s center: _________________________________ 5. This deep valley is formed as tectonic plates move apart and is found along a mid-ocean ridge: _______________________ ...
Geomagnetic reversal
A geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth's field has alternated between periods of normal polarity, in which the direction of the field was the same as the present direction, and reverse polarity, in which the field was the opposite. These periods are called chrons. The time spans of chrons are randomly distributed with most being between 0.1 and 1 million years with an average of 450,000 years. Most reversals are estimated to take between 1,000 and 10,000 years.The latest one, the Brunhes–Matuyama reversal, occurred 780,000 years ago;and may have happened very quickly, within a human lifetime. A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years. During this change the strength of the magnetic field dropped to 5% of its present strength. Brief disruptions that do not result in reversal are called geomagnetic excursions.