Earthquakes and volcanoes are natural phenomena resulting from the plate tectonics. In general, a volcanic eruption is accompanied by earthquakes. Read this ScienceStruck article to learn more about the relationship between these two natural processes.
Earthquakes refer to the shaking or trembling of the Earth’s crust as a result of abrupt release of energy. Fundamentally, they are seismic waves, generated by the natural phenomena or at times due to man-made events. Volcanoes, on the other hand, are openings in the Earth’s crust from which hot gases and molten rock materials are ejected onto the surface of the Earth.
Earthquakes and volcanic activity are closely related to each other. In fact, earthquakes usually accompany a volcanic eruption. Similarly, unusual earthquakes can also lead to volcanic eruptions. Before discussing the relationship between earthquakes and volcanoes, let’s take a brief look at each of them individually.
The size of an earthquake is represented by moment magnitude scale (MMS); a magnitude of 3 or lower is undetectable, whereas a magnitude equal to or greater than 7 causes maximum damage to life and property. The underground point where this process originates is called the hypocenter or focus. Epicenter refers to the point on the Earth’s surface, which is exactly above the hypocenter.
How are Earthquakes and Volcanoes Related
The planet Earth comprises irregular-shaped and varying-sized plates, which constantly move at different speeds. To be precise, the plates drift over the mantle layer of the Earth. Consequently, magma is generated along the plate boundaries.
When the plates collide, move apart, or slide each other, it leads to generation and accumulation of pressure (strain), which when released causes earthquakes. The strongest earthquakes are manifested during the plate collision, while the slowest earthquakes are observed when plates move apart from each other.
Similar to earthquakes, volcanic activity is observed when the plates are divergent (move apart) or convergent (move towards each other). In such plate movements, the magma present in the plate boundaries may rise to the Earth’s surface, leading to volcanic eruptions. Divergent plates may cause long volcanic rifts, whereas convergent plates result in individual volcanic eruptions.
In addition, both activities occur within a plate, which are referred to as intraplate earthquakes and volcanoes, respectively. It is estimated that about 10 percent of earthquakes are of this type.