Earthquakes 101 | National Geographic

Summary

Earthquakes are a powerful and destructive force caused by the movement of tectonic plates beneath the Earth's surface. The Earth's crust is made up of major plates that constantly shift, causing friction and seismic shock waves, which can lead to violent quakes. The most destructive quakes occur in subduction zones, where one plate is forced beneath another. These quakes can also trigger tsunamis, as seen in Japan and Indonesia. While it's impossible to predict earthquakes precisely, scientists and engineers are working to better understand and prepare for them, reducing their devastating impact and saving lives.

Takeaways

• 😀 Earthquakes are caused by the shifting and grinding of tectonic plates, which are constantly moving on the Earth's crust.
• 😀 The most destructive earthquakes often occur in subduction zones, where one tectonic plate is pushed beneath another.
• 😀 Earthquakes can create tsunamis when they occur under the ocean, leading to massive, deadly waves.
• 😀 On average, earthquakes kill around 10,000 people per year, with certain quakes resulting in much higher casualties.
• 😀 The 2010 Haiti earthquake was one of the deadliest, killing over 300,000 people.
• 😀 Every year, there are 500,000 detectable earthquakes worldwide, with 100,000 of them being felt and 100 causing damage.
• 😀 The Richter scale measures earthquake magnitude, with each whole number representing ten times more ground motion.
• 😀 The strongest recorded earthquake so far has not exceeded a magnitude of 9, but scientists predict at least one magnitude 8 or higher quake every year.
• 😀 The Earth's crust is constantly in motion, making earthquakes unpredictable but a natural part of our planet's activity.
• 😀 Engineers are working on designing stronger buildings to withstand earthquakes, and scientists are using data to predict their occurrence more accurately.

Q & A

What causes earthquakes?

Earthquakes are caused by the movement of tectonic plates beneath the Earth's surface. These plates constantly shift, bump, and grind against each other, creating friction that, when violent enough, produces seismic shock waves that cause the ground to shake.

What are tectonic plates and how do they move?

Tectonic plates are large slabs of land that make up the Earth's crust. These plates float on superheated magma beneath them and move slowly over time. Their movement causes them to shift, collide, or slide past one another, often resulting in earthquakes along the boundaries.

What is a subduction zone, and why is it significant for earthquakes?

A subduction zone is a location where one tectonic plate is forced beneath another. This process is significant for earthquakes because it can create violent quakes when one plate is pushed downward into the mantle while the other plate rises. Subduction zones are often associated with some of the most destructive earthquakes.

Can subduction zones cause tsunamis?

Yes, subduction zones can trigger tsunamis. When one plate is forced beneath another under the ocean, it can displace large amounts of water, generating massive, unstoppable waves that can cause significant destruction along coastlines.

What is the average death toll from earthquakes each year?

On average, earthquakes kill about 10,000 people each year. However, this number can vary significantly, with some earthquakes causing far higher fatalities, like the 2010 Haiti earthquake, which killed over 300,000 people.

How many earthquakes are detectable globally each year?

There are an estimated 500,000 detectable earthquakes around the world each year, though only around 100,000 of them can actually be felt and about 100 cause significant damage.

What is the Richter scale, and how is it used to measure earthquakes?

The Richter scale is used to measure the magnitude of earthquakes, running from 0 to 10. Every whole number increase on the scale represents 10 times more ground motion. A magnitude 10 earthquake would be 10 times more intense than a magnitude 9.

Has the Earth ever experienced a magnitude 10 earthquake?

No, in recorded history, the Earth has never experienced a magnitude 10 earthquake. While such a quake would be catastrophic, scientists predict that an earthquake with a magnitude of 8 or higher occurs on average at least once a year.

How are engineers working to protect buildings from earthquakes?

Engineers are designing stronger and more resilient buildings that can withstand the shaking from earthquakes. These buildings are built with materials and structures that allow them to absorb seismic forces, thereby reducing the likelihood of collapse during a quake.

Can scientists predict earthquakes?

Currently, scientists cannot predict the exact time and location of an earthquake. However, they can estimate the probability of an earthquake occurring in certain areas by analyzing seismic data and plate movements. In the future, advancements in this field may allow for better predictions.