Category: tectonic plates

Mapped: The World’s Major Earthquakes from 1956‒2022

This post is by Pallavi Rao from Visual Capitalist

Click to view this graphic in a higher-resolution.

This map highlights the epicenters of earthquakes on record between 1956 and 2022.

Mapping The World’s Major Earthquakes from 1956‒2022

Major earthquakes have occurred since time immemorial, but their observation and impact have not been evenly distributed around the globe.

On February 6, two earthquakes struck in Türkiye near the Syrian border. Both registered above a 7 on the Richter scale and have a combined death toll rapidly rising past 20,000 people.

And looking at the history of recent and ancient earthquakes, the location of these is no surprise. Using data from the United States Geological Survey (USGS), creator PythonMaps mapped earthquake epicenters between 1956 and 2022 that registered a 4.5 or higher on the Richter scale.

Tectonic Plate Movement and Earthquakes

Looking at the map, it’s easy to spot the concentration of earthquakes along the boundaries of Earth’s tectonic plates.

These massive moving slabs of rock fit together almost like puzzle pieces, making up the lithosphere or the upper crust. But as the edges of tectonic plates collide, slide against, and move away from each other, the crust cracks and folds and causes earthquakes.

Most of the earthquakes visualized on this map follow the boundaries of the seven major tectonic plates, along with the Philippine Plate (south of Japan) and the Nazca Plate (west of South America).

Here’s a list of the most earthquake-prone areas on the planet, according to the USGS.

Earthquake ZonesTectonic PlatesLocations
Ring of FirePacific, North American, Philippine, Juan de Fuca, Cocos, NazcaRim (Read more...)

Explainer: The Different Types of Volcanoes on Earth

This post is by Carmen Ang from Visual Capitalist

Click to view a larger version of the graphic.

Infographic explaining how volcanoes are formed and different types

Explainer: The Different Types of Volcanoes on Earth

Even if you don’t live near a volcano, you’ve been impacted by their activity.

It’s estimated that more than 80% of our planet’s surface has been shaped by volcanic activity. They’ve helped create our mountain ranges, plains, and plateaus, and have even helped fertilize the land that we now use to grow crops.

These critical mounds come in many shapes and sizes. This graphic by Giulia De Amicis provides a brief introduction to volcanoes, explaining their different types of shapes and eruptions.

Types of Eruptions

A volcano starts to form when molten rock rises from a crack in the Earth’s surface, which often emerge along tectonic plate boundaries.

Magma rises to the Earth’s surface because it’s lighter than rock. When it surfaces or erupts, it’s referred to as lava.

There are various types of volcanic eruptions, depending on the lava’s temperature, thickness, and composition. Generally speaking, high gas content and high ​​viscosity lead to explosive eruptions, while low viscosity and gas content lead to an effusive, or steadily flowing, eruption.

The Four Main Types of Volcanoes

Volcanoes vary in size and structure, depending on how they’re formed. Most volcanoes types fall into four main groups:

Shield Volcanoes

Shield volcanoes are built slowly, from low-viscosity lava that spreads far and quick. The lava eventually dries to form a thin, wide sheet, and after repeated eruptions, a mount starts to form.

From the top, these (Read more...)

Explainer: Earth’s Tectonic Plates

This post is by Carmen Ang from Visual Capitalist

explaining tectonic plate theory

Click to view a larger version of the graphic.

Explainer: Earth’s Tectonic Plates

It’s widely understood that Earth’s lithosphere (or outer crust) is made up of moving slabs of rock, better known as the tectonic plates.

These plates only move a couple of inches each year. However, these tiny movements add up over time and cause some of Earth’s most well-known phenomena. Today, the Earth looks a lot different than it did millions of years ago.

This graphic by Giulia De Amicis provides a brief explanation of plate tectonic theory and shows a map of the seven major plates.

Plate Tectonic Theory

In the early 20th century, German geologist Alfred Wegener published a paper on his theory called continental drift—a hypothesis that Earth’s continents were moving across Earth, and sometimes, even colliding into one another.

According to Wegener’s theory, Earth’s continents were once joined as a single, giant landmass, which he called Pangaea. But over time, Pangaea broke apart and formed the continents as we know them today.

Wegener couldn’t explain why this phenomenon was happening, so at the time, his theory was heavily criticized by his colleagues. But over the years, technological advances allowed scientists to study the Earth more closely, and geologists started to build on Wegener’s theory.

Discoveries like seafloor spreading helped explain the “why” behind continental movement, and eventually, Wegener’s initial continental drift theory morphed into plate tectonic theory. And now, the idea that Earth’s crust is slowly moving beneath our feet is widely (Read more...)