Rapid southward motion of the Hawaiian plume, followed by a sharp slowdown, causes the sharp bend in the Hawaiian-Emperor seamount chain.“These findings suggest the shape of volcanic seamount chains record motion in the deepest mantle, near the Earth’s core.
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How was the Hawaiian Emperor island chain formed?
The Hawaiian Emperor seamount chain is a well-known example of a large seamount and island chain created by hot-spot volcanism.While the hot spot itself is fixed, the plate is moving. So, as the plate moved over the hot spot, the string of islands that make up the Hawaiian Island chain were formed.
What does the bend in the chain at 50 Ma indicate about the direction of the Pacific Plate movement?
A sharp bend in the chain indicates that the motion of the Pacific Plate abruptly changed about 43 million years ago, as it took a more westerly turn from its earlier northerly direction.
What is the evidence that the Hawaiian island Emperor seamount chain is a hotspot?
Scientists believe this hot spot has been expelling lava for roughly 70 million years. Many of these landforms created by volcanoes are still submerged. Also submerged are the peaks of the Emperor Seamount to the northwest of Hawai’i, which is part of the same chain of volcanic formations.
What causes the Pacific Plate to move?
The Pacific Plate is being moved north west due to sea floor spreading from the East Pacific Rise (divergent margin) in the Gulf of California. The North American Plate is being pushed west and north west due to sea floor spreading from the Mid Atlantic Ridge (divergent margin).
What caused the bend in the Hawaiian Island Emperor seamount chain and when did the bend form?
A crash caused the bend
By about 50 million years ago, the northern migration of subduction led to a colossal collision between the island arc at the northern end of the Pacific Plate and the northeast edge of Asia.
What are the causes of plate motion?
The force that causes most of the plate movement is thermal convection, where heat from the Earth’s interior causes currents of hot rising magma and cooler sinking magma to flow, moving the plates of the crust along with them.In ridge push and slab pull, gravity is acting on the plate to cause the movement.
What two reasons have been stated to explain the bend in the Hawaiian and Emperor seamount island chains in the Pacific Ocean?
A conspicuous 60° bend of the Hawaiian-Emperor Chain in the north-western Pacific Ocean has variously been interpreted as the result of an abrupt Pacific plate motion change in the Eocene (∼47 Ma), a rapid southward drift of the Hawaiian hotspot before the formation of the bend, or a combination of these two causes.
What likely caused the bend in the seamount chain north of the main Hawaiian Islands?
The Emperor and Hawaiian chains form an angle of about 120°. This bend was long attributed to a relatively sudden change of 60° in the direction of plate motion, but research conducted in 2003 suggests that it was the movement of the hotspot itself that caused the bend.
How was the Hawaiian Emperor island chain formed quizlet?
The Hawaiian Islands were formed by volcanic activity. The Hawaiian Emperor seamount chain is a well-known example of a large seamount and island chain created by hot-spot volcanism. Each island or submerged seamount in the chain is successively older toward the northwest.
What is the name of the newest seamount to form in the Hawaiian island chain?
Lö’ihi Seamount
In fact, there is a new island being formed to the southeast of Hawaii as we speak. It is called the Lö’ihi Seamount and represents the next island in the Hawaiian Island chain as the Pacific Plate continues to move over the Hawaiian hotspot.
How are islands formed by plate tectonics?
When tectonic plates are pushed and pulled apart, they form volcanoes, causing eruptions when the plates are pulled apart. As hot magma rises from the crevasses created, it eventually builds up to form islands.
What causes hot spot volcanism?
A volcanic “hotspot” is an area in the mantle from which heat rises as a thermal plume from deep in the Earth. High heat and lower pressure at the base of the lithosphere (tectonic plate) facilitates melting of the rock. This melt, called magma, rises through cracks and erupts to form volcanoes.
How was the Pacific Plate formed?
The Pacific Plate originated at the triple junction of the three main oceanic plates of Panthalassa, the Farallon, Phoenix, and Izanagi Plates, around 190 million years ago.
What is the Pacific Ring of Fire?
The Ring of Fire, also referred to as the Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes. Its length is approximately 40,000 kilometers (24,900 miles).
How are the tectonic plates moving?
The main driving force of plate tectonics is gravity. If a plate with oceanic lithosphere meets another plate, the dense oceanic lithosphere dives beneath the other plate and sinks into the mantle.The sinking oceanic lithosphere drags the rest of the tectonic plate and this is the main cause of plate motion.
What will eventually happen to the islands we now know as the Hawaiian Islands?
The island erodes and the crust beneath it cools, shrinks and sinks, and the island is again submerged. Millions of years from now, the Hawaiian Islands will disappear when the edge of the Pacific plate that supports them slides under the North American plate and returns to the mantle.
What global tectonic event happened 40 million years ago?
40 Million Years Ago
Forty million years ago, a large tectonic plate, known as the Farallon Plate, was between the Pacific and North American plates. Subduction of the Farallon Plate beneath the entire West Coast created a line of volcanoes from Alaska to Central America.
What force causes most of the plate movement?
Research has shown that the major driving force for most plate movement is slab pull, because the plates with more of their edges being subducted are the faster-moving ones. However, ridge push is also presented in recent research to be a force that drives the movement of plates.
What force that causes the plates to move?
gravity
Heat and gravity are fundamental to the process
The energy source for plate tectonics is Earth’s internal heat while the forces moving the plates are the “ridge push” and “slab pull” gravity forces. It was once thought that mantle convection could drive plate motions.
What is the cause of tectonic plate motion quizlet?
Circular currents in the mantle caused by the magma being heated by the core off the Earth. The region where oceanic plates sink down into the asthenosphere.Describe how convection currents might be the cause of plate tectonics. They might be the cause because the movement of the plates pushes the plates to move.
