A huge piece of Earth is under the sea. 

A huge piece of Earth sits under the sea. 
This big piece grew over a long time. It took over much of the ocean floor. It even made some other pieces disappear. 
Some parts of this piece are land. You can find land in New Zealand. There is also land in California.
This piece moves near other big pieces. Sometimes they slide past each other. Sometimes one piece slides under another. The ocean floor is always changing.
The Pacific plate is a giant piece of the Earth's crust. It sits under the Pacific Ocean. It is the largest tectonic plate, which is a massive piece of the Earth's outer shell. 
This plate began forming 190 million years ago. It grew by taking up space from other plates. This growth destroyed the Izanagi plate. It also made the Farallon and Phoenix plates much smaller. The plate is mostly made of ocean floor. However, it does have some land in New Zealand and California. 
The plate moves in many ways. In some spots, it slides under other plates. This is called subduction. Subduction makes deep places like the Mariana Trench. In other spots, plates slide past each other. The San Andreas Fault is one such place. A hot spot, or a place where heat comes up, also sits inside the plate. This hot spot helps make the Hawaiian Islands. The oldest parts of the plate are near the Mariana Trench. These old parts are slowly being pulled into deep trenches near Asia.
The Pacific plate is a huge part of the Earth's outer shell. It sits deep under the Pacific Ocean. This plate is the largest tectonic plate on our planet. 
This plate grows and moves in many different ways. In some areas, plates move apart at a divergent boundary. This happens at places like the Explorer Ridge or the East Pacific Rise. In other spots, plates slide past each other. This is called a transform boundary. The San Andreas Fault is a famous example of this. Sometimes, one plate slides under another in a process called subduction. This creates deep places like the Mariana Trench.
This giant plate has a very long history. It first began to form about 190 million years ago. It started as a small microplate at a triple junction. A triple junction is where three different plates meet. At that time, the plates were called the Farallon, Phoenix, and Izanagi plates. As the Pacific plate grew, it changed the map of the world. It even destroyed the Izanagi plate by pulling it under Asia.
There are many specific facts about this plate's edges. The northern side forms the Aleutian Trench and the Aleutian Islands. To the west, it meets the Okhotsk plate at the Japan Trench. The southern edge meets the Antarctic plate at the Pacific–Antarctic Ridge. 
Think of the plate like a giant puzzle piece. It is constantly bumping into its neighbors. This movement creates many things we see today. For example, a hot spot inside the plate formed the Hawaiian Islands. The edges of the plate also create deep trenches in the sea. These trenches act like places where the old ocean floor is recycled. This cycle keeps the Earth's surface changing all the time.
The Pacific plate is a massive section of the Earth's lithosphere. This lithosphere is the rigid outer shell of our planet. The Pacific plate sits deep beneath the Pacific Ocean. It is currently the largest tectonic plate on Earth. 
This plate moves in several distinct ways depending on its boundaries. At a divergent boundary, plates move away from each other. For example, the north-eastern side meets the Explorer, Juan de Fuca, and Gorda plates at ridges. The south-eastern side meets the Nazca plate at the East Pacific Rise. A transform boundary occurs when plates slide past one another. The San Andreas Fault is a famous transform boundary between the Pacific and North American plates. Finally, a convergent boundary happens when plates move toward each other. This often leads to subduction, where one plate sinks beneath another.
The edges of the Pacific plate are very complex. In the north, it subducts under the North American plate. This process creates the Aleutian Trench and the Aleutian Islands. To the west, it meets the Okhotsk plate at the Japan Trench. The western side also features a convergent boundary with the Philippine Sea plate. This subduction creates the Mariana Trench, which is one of the deepest parts of the ocean. In the southwest, the plate has a complex relationship with the Indo-Australian plate. It subducts under that plate north of New Zealand to form the Tonga and Kermadec Trenches.
The history of this plate began approximately 190 million years ago. It started as a small microplate at a triple junction. A triple junction is a point where three different plates meet. At that time, the junction involved the Farallon, Phoenix, and Izanagi plates. The junction became unstable because a kink developed in one of the plate boundaries. This instability caused the triple junction to be surrounded by transform faults. This event marked the beginning of the Pacific plate's long growth.
As the Pacific plate grew, it changed the shape of the ancient oceans. It eventually covered most of the Pacific Ocean basin. This growth had a major impact on its neighbors. The Farallon plate was reduced to small remnants along the Americas. The Phoenix plate was also reduced to a small remnant near the Drake Passage. Most significantly, the Pacific plate destroyed the Izanagi plate. It did this by pulling the Izanagi plate into subduction under Asia. 
Geologists can see the age of the seafloor by looking at the plate. The seafloor shows a "stairstep" pattern of different ages. The youngest parts of the floor are near the ridges. The oldest parts are being consumed in oceanic trenches near Asia. The oldest members of the seabed geology are found in these eastern Asian trenches. Some of this oldest crust dates back to the early Cretaceous period. This was between 145 and 137 million years ago. The oldest section is called the "Pacific Triangle." It is located just east of the Mariana Trench.
There are several notable features within the plate itself. One important feature is an interior hot spot. This hot spot is responsible for forming the Hawaiian Islands. The plate also contains the largest block of continental crust in the southern part of Zealandia. Scientists like Hillis and Müller suggest the Bird's Head plate might move with the Pacific plate. However, other researchers like Bird believe they are not connected. These different movements and features show how active the Pacific plate remains.
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