Pacific Plate – On the earth itself it consists of various kinds of plates, one of the plates on earth is the Pacific plate. In fact, this Pacific plate passes through Indonesian territory. The Pacific plate is also known as the Pacific Ring of Fire. Then, what exactly is meant by the Pacific plate? Check out the full review below, You.
The theory of plate tectonics
The theory of plate tectonics or in English is also called Plate Tectonics is a major theory in a field of geology which is then developed in order to provide an explanation of the existence of evidence of movement on a large scale that is carried out naturally by the earth’s lithosphere.
In addition, this theory includes and replaces several theories of continental drift. The theory of continental drift itself was expressed more or less in the 20th century which was accompanied by the concept of seafloor spreading which was also developed around the 1960s.
So, the outermost part of the earth is formed by two layers. The top layer is the lithosphere which consists of the crust and at the very top is the earth’s mantle which is dense and rigid inside.
Then, at the bottom of the asthenosphere’s lithosphere layer, although it is solid, it can still flow like a very slow liquid. In addition, if you use the geological time scale, then the time is very long. This is because of the viscosity and also the very low shear strength.
If you look deeper, the layers of the lithosphere are further divided into tectonic plates . There are also seven main plates and many smaller ones on Earth. These plates ride on the asthenosphere. They move relative to one another at plate boundaries, either divergently (away), convergently (collide), or transform (sideways).
Earthquakes, as well as volcanic activity, mountain building, and oceanic trench formation can all occur in areas along plate boundaries. The lateral movement of the plates is usually between 50–100 mm/a
About the Pacific Plate
The Pacific Plate is the largest of the 7 major tectonic boundaries. This plate has a size of 102,900,000 km2 or twice the size of the South American Plate. The Pacific Plate itself is on the seabed of the Pacific Ocean.
When talking about the Pacific plate, it cannot be separated from what is called plate tectonics. In plate tectonics, there are so-called odd plate tectonics. The name arises because these plates generally consist of oceanic crust and also continental crust. The example is on the Pacific plate that underlies the Pacific Ocean with the Hawaiian Islands positioned in the middle.
Back again to the Pacific plate. The Pacific plate stretches from the west coast of North America to Alaska. Then, on the western edge, this plate extends to the east coast of the islands of Japan and Indonesia.
Not only that, most of the Pacific Ring of Fire was formed because of the Pacific plate. This Pacific plate has a horseshoe pattern, so that on this plate earthquakes and volcanic eruptions will usually occur when compared to countries that this plate does not pass through.
The movement of this plate is estimated to move at a speed of 5-10 cm per year. Even so, the Pacific plate, Cocos plate, Antarctic plate, and the Nazca plate can move more than 10 cm per year, so their movement is faster when compared to other tectonic plates.
A geological map of the seafloor of the Pacific Ocean also reveals that geological sequences occurred over millions of years, forming the Ring of Fire at the largest ocean boundary. The Pacific plate can also show the chronology of the Pacific ocean floor by ladder step, with the oldest being substituted for the Asia Pacific Trench itself 145 million years ago.
Within a few years, the Pacific Plate along with the Pacific Basin began to shrink. This could occur at a time when North America and South America begin to move in a southerly westward direction, thereby expanding the Atlantic Ocean and compromising the Pacific Ocean.
The Pacific Plate as the Pacific Ring of Fire
The Pacific plate then forms most of the Pacific Ring of Fire. This pattern of plate tectonics is responsible for some of the most severe earthquakes and volcanoes in the world. This subduction along the outer boundary of the Pacific Ocean produces large arcs that can create earthquakes and volcanic activity. Therefore, this Pacific plate is also known as the Pacific Ring of Fire.
The Pacific Plate can be said to have a role as a “museum” of paleo-geology under the sea. That means, it contains the largest area with the oldest geological remains of the cast under the seafloor in the Asian oceanic trenches. There is evidence that the small Juan de Fuca, Nazka, and Cocos plates are remnants of an earlier plate, later called the Farallon.
Later, research records show that the Juan de Fuca, Nazka, and Cocos small plates are remnants of an earlier plate, also known as the Farallon. This is based on a geological map on the seabed of the Pacific Ocean which reveals that geological sequences took millions of years to finally form the Ring of Fire at the largest ocean boundary.
The Pacific plate will also show the chronology of the Pacific ocean floor, with the oldest then referring to the Asia Pacific Trench that existed from 145 million years ago. It also formed when the continents of North America as well as South America moved westward, expanding the Atlantic Ocean at the expense of the Pacific itself.
Pacific Plate Boundary
The Pacific Plate itself has stretched, starting from the west coast of North America all the way to Alaska. Then, on the west side, the Pacific plate stretches long enough to the east coast. Therefore, this Pacific plate also passes through the Japanese islands and also Indonesia.
The Pacific Plate itself is at a divergent boundary with the Explorer Plates, Juan de Fuca and Gorda which then successively form the Explorer Ridge, Juan de Fuca and Gorda, to the north on the east side.
Then, towards the middle on the east side, there is a transition boundary with the North American plate. The boundary runs along the San Andreas Fault which is directly adjacent to the cocos plate.
Then to the south there is also a divergent boundary with the Nazca plate. From this boundary produces an East Pacific Rise. In addition, in this southern part there is also a divergent boundary with the Antarctic plate which forms the Antarctic Pacific Ridge.
Continuing to the west edge there is a convergent boundary that is subducting at the bottom of the Eurasian plate. Then, to the north there is the Philippine plate which is in the middle and forms the Mariana Trench. Then, in the south, this Pacific plate has a convergent boundary with the Indo-Australian plate, which then subducts beneath it to northern New Zealand.
The Alpine Fault is a sign of the transitional boundary between the two plates. In addition, in the north there is a convergent boundary that subducts under the North American Plate which then forms the Aleutian Trench and the nearby Aleutian Islands.
The Driving Force of Plate Movement
The movement of tectonic plates can occur due to the relative density of the oceanic lithosphere and the relatively weaker character of the asthenosphere. This release of heat from the mantle has been obtained and is the original source of energy that drives plate tectonics.
The view or opinion that is currently approved is that the excess density of the oceanic lithosphere makes it infiltrate under the subduction zone, resulting in the strongest source of plate movement. Even so, such a view is still debated.
Then, at the time of its formation or at the mid-oceanic ridge, the oceanic lithosphere initially has a lower density than the asthenosphere and its surroundings. However, the density binds over time. This can happen because of the cooling and thickening process.
The large density of the old lithosphere then relative to the asthenosphere below allows intrusion into the deep mantle at subduction zones, thus being the source of most of the power in plate movements. One of the weaknesses of the asthenosphere is that it allows the plates to move easily toward the subduction zone.
Although subduction is believed to be the strongest driving force for plate movements, there are still other driving forces which are later proven by the existence of plates such as the North American plate, as well as the Eurasian plate which then moves but does not experience subduction anywhere.
This driving source itself is still a topic of intensive research and discussion among earth science scientists. Two- and three-dimensional imaging of the Earth’s interior (seismic tomography) showing a more heterogeneous density distribution laterally throughout the mantle.
These variations in density can themselves be material (from rock chemistry), mineral (from variations in mineral structure), or thermal (through thermal expansion and contraction from heat energy). The manifestation of this laterally heterogeneous density is mantle convection of buoyancy forces.
About how this mantle convection is very directly related and not related to planetary movements, so it is still a field that is being studied and discussed in geodynamics. One way or another, this energy must then be transferred to the lithosphere for the tectonic plates to move. There are two main types of forces that affect planetary motion, namely friction and gravity.
Every plate movement in the world, especially in Indonesia, will usually have an impact on the area around the plate. Although it is not known exactly why plates can move, it never hurts to always be alert to natural disasters that will occur when there is plate movement.