Are Earthquakes Good? You Bet!!

I have read Chapter 9, of Rare Earth by Ward and Brownlee, “The Surprising Importance of Plate Tectonics” to try to understand why we have earthquakes and whether they do any good as far as life on earth is concerned.

Actually, I find that the phenomena of plate tectonics is very important to the development and maintenance of life on earth!

The earth has a core of solid iron, but the outer part of the core is liquid iron heated above the melting point by radioactive isotope degeneration. Outside of that is a vast amount of liquid magma, which we know as basalt. Convection currents in this liquid, overheated, basalt cause the hottest parts to rise to the surface where it cools and becomes more dense or actually solidifies. Then, the more dense basalt sinks into the earth causing movement of the liquid and convection currents. The rising and sinking of basalt is called “subduction.” This “boiling” motion causes movement in the thin, outer crust of the earth, and huge chunks move around much as a scum of congealed liquid might move about in a pot boiling on the kitchen stove. The movement of these crustal elements is what geologists call “plate tectonics.” These moving plates colliding with one another are the cause of earthquakes. The collisions cause the rise of parts of the earth’s crust and the formation of continents and linear mountain ranges. Without plate tectonics, we would not have any dry land on earth.

As the hot basalt rises to the surface of the earth, it sometimes breaks forth into the atmosphere causing volcanoes. These volcanoes occur dozens of times every year; and they usually do not do any harm; but they receive lots of media coverage. A volcano discharges huge amounts of carbon dioxide into the atmosphere; and are the main sources of greenhouse gasses that allow the maintenance of warmth from the sun to remain on our earth—without this CO², the earth would be a frigid, frozen, place, where life would be impossible. Volcanoes are the primary source of greenhouse gasses on the earth.

As the earth spins, and the inner core of solid and liquid iron lags behind the spin of the earth, a magnetic field is created around the planet. This magnetic field protects the earth from the bombardment of vast numbers of subatomic particles that are racing through outer space. The particles are electrons, protons, and helium nuclei that emanate from the sun and from star explosions in distant areas of the universe. These particles would kill off all life on earth if they were not prevented from doing that by earth’s magnetic field.

The movement of tectonic plates also contributes to the growth of bacteria in the oceans of the planet. This happens because of the recycling of nutrients into the oceans of the planet—these nutrients are necessary for the growth of microscopic life forms. Bacteria and other microorganisms are the source of oxygen in our atmosphere which allow the development and growth of complex animal life. We are indebted to plate tectonics for the presence of an oxygen-rich atmosphere, which allows and facilitates the animal life on this planet.

WE COULD NOT LIVE WITHOUT EARTHQUAKES!!