Category: tectonic plates

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...)