The ground can shake. Big pieces of Earth move. They rub against each other. This makes a big shake. It can even make big waves. This is how the Earth moves. Do you feel the ground shake?
The Earth is made of big pieces. These pieces rub against each other. They can get stuck. This builds up a lot of force. Suddenly, the pieces slip. This makes the ground shake.
These shakes can move through the ground. They can also move along the surface. Sometimes, they happen under the sea. This can push the water up. It can make big waves.
Most big shakes happen between these pieces. These shakes are very common. They happen in many lands. They can happen in places like Japan or Chile. Scientists watch for small shakes first. This helps them know a big shake might come. It is a busy world beneath our feet.
Earth has big pieces called tectonic plates. These plates move around. Most earthquakes happen between these plates. We call these interplate earthquakes. They make up 90 percent of all seismic energy on Earth.
Sometimes, plates try to move past each other. They get stuck. This builds up stress. When the plates finally slip, they release that stress. This slip makes seismic waves. These waves travel through the ground. They can also move along the surface.
Plates can move in different ways. They can slide sideways at a transform fault. They can move apart at a divergent boundary. They can also crash together at a convergent boundary. When one plate slides under another, it is called subduction. These can cause megathrust earthquakes. These are often the largest earthquakes on Earth.
Some earthquakes can even make tsunamis. This happens when a slip moves the seafloor. The movement pushes the water up. This makes huge waves. Scientists watch for small tremors first. These small shakes can happen days or weeks before a big one. This helps them prepare for the danger.
An interplate earthquake happens at the edge where two tectonic plates meet. These plates are huge pieces of the Earth's outer shell. Most of the energy released by earthquakes comes from these boundaries. In fact, they account for more than 90 percent of all seismic energy. This makes them very important to study. They are different from intraplate earthquakes, which happen inside a single plate.
These earthquakes work through a buildup of stress. When two plates try to move past each other, they often get locked together. They cannot slide easily, so energy builds up at the boundary. Eventually, the stress becomes too much and the plates slip. This sudden movement is called brittle failure. The slip creates seismic waves that travel through the Earth. These waves move through the ground and along the surface.
There are three main ways these plates move. At a transform fault, the plates slide sideways past each other. At a divergent boundary, the plates move apart. At a convergent boundary, one plate moves toward another. Sometimes, one plate even slides under the other in a process called subduction. These subduction events can cause megathrust earthquakes. These are the largest earthquakes on our planet.
Scientists have found some interesting patterns in these events. Sometimes, small tremors happen days or weeks before a large earthquake. These are called precursory tremors and are linked to slow slips. Also, interplate earthquakes can cause tsunamis. This happens if the sudden slip moves the seafloor and pushes the water up. While many are not strong enough to cause them, some can create huge waves.
Many famous large earthquakes have been interplate events. Since 1900, there have been several massive quakes with a magnitude of 9.0 or higher. In 1960, a magnitude 9.5 quake hit Bio-Bio, Chile. In 1964, a magnitude 9.2 quake struck Southern Alaska. More recently, a magnitude 9.1 quake hit near Honshu, Japan, in 2011. Another magnitude 9.1 quake occurred off Sumatra in 2004. These events show how much energy moves at plate boundaries.
An interplate earthquake is a seismic event that occurs at the boundary between two tectonic plates. These plates are the massive sections of the Earth's outer shell. Interplate earthquakes are incredibly powerful and significant. They account for more than 90 percent of the total seismic energy released around the world. This makes them the primary drivers of most earthquake activity on our planet. While they are different from intraplate earthquakes, which occur within a single plate, interplate events are the most common source of large-scale geological change.
The mechanism behind these earthquakes involves a process of stress accumulation and sudden release. As tectonic plates move, they often attempt to slide past, away from, or into one another. Because of friction, the plates can become locked together at the boundary. As the plates continue to push, stress builds up at the fault line. Eventually, this stress reaches a point where the rock can no longer hold it. This leads to brittle failure, where the rock breaks and the plates suddenly slip relative to each other. This rapid displacement creates seismic waves that travel through the Earth's interior and along its surface.
There are three distinct types of plate boundaries where these earthquakes happen. At a transform fault, the plates slide laterally, or sideways, past one another. At a divergent boundary, the plates move apart from each other, often creating rift zones through normal faulting. At a convergent boundary, plates move toward each other. In many convergent zones, one plate undergoes subduction, meaning it slides beneath another plate. These specific subduction events can produce megathrust earthquakes. Megathrust earthquakes are a special category that includes most of the largest earthquakes ever recorded.
Scientists have observed specific patterns that may help predict these events. Sometimes, interplate earthquakes are preceded by an irregular occurrence of small tremors known as precursory tremors. These tremors are often associated with a process called slow slip along the plate boundary. Researchers have found that these small movements can sometimes be identified within days or weeks of a major earthquake. By studying these tremors, scientists hope to develop better strategies to mitigate damage and anticipate when a large event might occur.
Interplate earthquakes can be distinguished from intraplate earthquakes by several scientific measurements. One key difference is the stress drop, which measures the stress across a fault before and after a rupture. Interplate earthquakes have stress drop values that are systematically smaller by a factor of 6 compared to intraplate earthquakes. This suggests that the boundaries between plates are significantly weaker than the plates themselves. Additionally, while intraplate earthquakes release stress gradually, interplate earthquakes release their stress immediately. This immediate release can lead to significant effects like seafloor uplift. If this happens underwater, it can transfer energy to the water and generate a tsunami.
History provides many examples of the immense power of interplate earthquakes. Since 1900, several massive earthquakes with a magnitude of 9.0 or higher have been recorded. In 1960, a magnitude 9.5 earthquake occurred in Bio-Bio, Chile. In 1964, Southern Alaska experienced a magnitude 9.2 event. More recently, in 2011, a magnitude 9.1 earthquake struck near the east coast of Honshu, Japan. In 2004, another magnitude 9.1 earthquake occurred off the west coast of northern Sumatra. These specific events demonstrate the massive scale of energy released at plate boundaries.
Understanding these events is vital because they affect many different regions and systems. Certain areas are particularly prone to interplate earthquakes due to their location on prominent plate boundaries. These include the west coast of North America, particularly California and Alaska. Other high-risk regions include the northeastern Mediterranean, such as Greece, Italy, and Turkey. Other notable areas include Iran, New Zealand, Indonesia, India, Japan, and parts of China. Because earthquakes with magnitudes higher than 5 in populated areas are highly dangerous, studying these boundaries is essential for human safety and property protection.
Where will your curiosity go next?
More to explore
✨ What else?
Related topics you might enjoy
🔬 Go deeper
More advanced topics to explore
🪜 Step back
Simpler topics to build understanding
What is Nepedia?
A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.