Unit 2
evidence the supports the theory of continental drift?
in the early part of the 20th century, scientists began to put together evidence that the continents could move around on Earth's surface. The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones.
what is the theory of seafloor spreading
the formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid ocean ridges and its subsequent outward movement on either side.
what are three main types of plate boundaries
The three main plate boundaries are convergent, divergent, and transform.
Describe paleomagnetism
the branch of geophysics concerned with the magnetism in rocks that was induced by the earth's magnetic field at the time of their formation.
Who created the theory of continental drift?
Alfred Wegener
what is a divergent plate boundary?
A divergent plate boundary is where two lithospheric plate are moving apart.
What is a fualt?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep. .
what is a convergent plate boundary?
A lithospheric plate boundary where two plates come together.
What is a plate boundary?
A plate boundary is the area where two different lithospheric plates meet.
What is a subduction zone?
A subduction zone is where one plate goes under another plate.
what is a transform plate boundaries
A transform fault boundary is a lithospheric plate boundary where two plates slide past each other.
What is an earthquake?
An earthquake is what happens when two blocks of the earth suddenly slip past one another.The surface when they slip is called fault or fault plane the location below the earth's surface where the earthquake starts is called the hypocenter and the location directly above it on the surface of the earth is called epicenter.
whats the theory of continental drift?
Continental drift describes one of the earliest ways geologists thought continents moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics.
who developed the theory of seafloor spreading
Harry Hess
what is the name of the mid-ocean range in Atlantic ocean
MAR
where is an earthquake most likely to occur?
Most earthquakes occur along the edge of the oceanic and continental plates. The earth's crust (the outer layer of the planet) is made up of several pieces, called plates.
How are mountains created?
Mountains are created when forces inside the earth's crust cause the land to uplift.
What are mountains?
Mountains are large landforms made of rock that have been elevated high above the surrounding land.
what is another type of fault
Normal faults create space. Two blocks of crust pull apart, stretching the crust into a valley.
what is the third type of fault
Reverse faults, also called thrust faults, slide one block of crust on top of another.
how do scientists identified where the plate boundaries are located
Scientist have identified the boundaries between plates, because this is where earthquakes, and volcanic eruptions happen most frequently.
how do scientists measure the motion of the plate
Scientist measure the motions of plates by using global positioning system technology (GPS).
what is the evidence that helps the theory of seafloor spreading
Several types of evidence supported Hess's theory of seafloor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves. This evidence led scientists to look again at Wegener's hypothesis of continental drift.
whats one type of fault
Strike-slip faults indicate rocks are sliding past each other horizontally, with little to no vertical movement
name three types of mountains?
The 3 types of mountains are: folded mountains, fault-block mountains, and volcanic mountains.
where could I find these two types of divergent plate boundaries on earth today?
The Mid-Atlantic Ridge in the middle of the Atlantic Ocean would be an example of an oceanic-oceanic divergent boundary. The Great Rift Valley in Eastern Africa would be an example of a continental-continental divergent boundary.
how do we measure earthquake?
The Richter scale measures the largest wiggle (amplitude) on the recording, but other magnitude scales measure different parts of the earthquake
What is the San Andreas Fault?
The San Andreas Fault is a place where two tectonic plates touch, the North American and Pacific Plates. The plates are rigid (or almost rigid) slabs of rock that comprise the crust and upper mantle of the Earth. The SAF is about 700 miles long as the crow flies and about 800 miles long when its curves are measured. It is roughly ten miles deep, and reaches from the Salton Sea in Imperial county to Cape Mendocino in Humboldt county.
the theory of plate tectonics
The Theory of Plate Tectonics states that Earth's outer layer is made up of plates, which have moved throughout Earth's history. The theory explains the how and why behind mountains, volcanoes, and earthquakes, as well as how, long ago, similar animals could have lived at the same time on what are now widely separated continents.
What is the epicenter of an earthquake?
The epicenter is the point on the earth's surface vertically above the focus, point in the crust where a seismic rupture begins.
what features and events occur along these boundaries
The feature that is created is a transform fault. A fault is a region on Earth's surface that is broken and where movement takes place. Earthquakes also happen frequently along these boundaries.
What is the focus of an earthquake?
The hypocenter is the point within the earth where an earthquake rupture starts. The epicenter is the point directly above it at the surface of the Earth. Also commonly termed the focus.
What is the lithosphere?
The lithosphere is the physical or mechanical layer of the Earth made up of both continental and oceanic crust, and the rigid part of the upper mantle.
how does the lithosphere move?
The lithosphere moves because it is riding on top of the asthenosphere which has convection cells flowing in it. The lithospheric plates move in the direction that the convection is flowing under them.
Why was the theory of continental drift rejected?
The main reason that Wegener's hypothesis was not accepted was because he suggested no mechanism for moving the continents. He thought the force of Earth's spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.
name 6 major mountains ranges in the usa
The major mountain ranges in the US are the: Rocky mountains, Cascade Mountains, Sierra Nevada Mountains, Appalachian Mountains, Alaska Mountains, Brooks Mountains.
what is a mid-ocean ridge
The mid-ocean ridge is the most extensive chain of mountains on Earth, stretching nearly 65,000 kilometers (40,390 miles) and with more than 90 percent of the mountain range lying in the deep ocean.
what is going to happen to cali. because the movement along San Andrea's fault.
The part of California that is on the Pacific plates is slowly breaking away from the part that is on the North American plate.
what are three types of convergent plate boundaries and what topographic features and events occur along these boundaries?
The three types of convergent plate boundaries are oceanic-oceanic, continental-continental, and oceanic-continental. The features and events that happen along an oceanic-oceanic convergent boundary are deep ocean trench, volcanic island arc, earthquakes, and volcanic activity. The features and events that happen along an oceanic-continental convergent boundary are deep ocean trench, volcanic mountain ranges, earthquakes, and volcanic activity. The features and events that happen along a continental-continental convergent boundary are mountain ranges, and earthquakes.
what are two types of divergent plate boundaries, and what topographic features and events occur along these boundaries
The two types of divergent plate boundaries are oceanic - oceanic divergent boundary, and continental - continental divergent plate boundary. The feature that occur along oceanic - oceanic divergent boundaries are mid-ocean ridges. Events that happen along oceanic-oceanic divergent boundaries are volcanic activity and earthquakes. The feature that is created along continental-continental divergent boundary is a rift valley. Volcanic activity and earthquakes are also common events that happen.
What causes an earthquake?
When two tectonic plates slide past each other made release waves of energy.
where could I find these three types of convergent boundaries on earth today?
You could find an oceanic-oceanic convergent boundary between the Pacific Plate and Eurasian Plate. This is why the Islands of Japan were created. You could find an oceanic-continental convergent boundary between the Nazca Plate and the South American Plate. This is why the Andes Mountain Range was created, and why there are many volcanoes in this range. You could find a continental-continental convergent boundary between Indo-Australian plate and the Eurasian plate. This is why the Himalaya Mountain range was created.
what mountain range in the usa existed during pangea
central pangean mountains
what evidence did glaciers leave for the existence of pangea
glossopteris
