The Real Truth, a magazine restoring plain understanding

Understanding Earthquakes and Volcanoes—and Their Role in Prophecy

By Jeffrey D. Davis

September 08, 2009

In recent history, mankind has come to understand the structure of the earth—the core, the mantle and the crust. We have learned of tremendous forces near the planet’s surface capable of immense destruction. This has helped us better understand how earthquakes occur.

Earth’s core is approximately 4,000 miles from the surface and is made of superheated metals. Our planet consists of a solid inner core and a liquid outer core. Beyond the outer core lies the mantle, which is 1,800 miles thick and consists of semi-molten and semi-solid rock. The mantle has a soft consistency and is often referred to as the “hot plastic layer.”

On top of the mantle float large semi-rigid slabs called tectonic plates, which form most of the earth’s crust. These plates are thousands of miles wide, but only three to 45 miles thick. If our planet was the size of an apple, the thickness of the crust would be less than that of the apple’s skin.

The plates’ visible surfaces are landmasses known as continents. For most continents, such as Africa and the Americas, the plate’s boundary coincides with the shoreline. The edges of tectonic plates—the borders between two plates—are areas of geological turbulence giving rise to visible fault lines.

A fault system borders Africa along the Red Sea and Suez Canal in the northeast, and continues along the main continental plate in eastern Africa. The western border, in the middle of the Atlantic Ocean, is called the Mid-Atlantic Ridge, which is also the border of the South American plate to the west and extends 12,000 miles, from Antarctica all the way to the North Pole. It divides the North American and Eurasian plates as well.

This ridge was formed by the movement of the tectonic plates. As the plates pull apart, magma from underneath the plates is released and rushes upward to fill the breach—one example of how the earth is self-sustaining.

When the movement of tectonic plates becomes restrained by the friction between plates, tension builds.

Earthquakes occur when the edges of the plates can no longer withstand the pressure and break down—releasing the tension.

These plates move very slowly, usually no more than five inches a year. However, periods of no movement are interpreted as danger signals. When movement is restricted, energy is being stored up for a powerful earthquake.

Seismographs (instruments that measure ground movement) around the world detect about 30,000 earthquakes per year, with millions of smaller earthquakes also estimated to occur. On average, there is one extremely severe earthquake each year, such as the 9.3 magnitude earthquake that unleashed the late 2004 Indian Ocean tsunami.

Moderate earthquakes—such as the December 2003 quake of San Simeon, Calif., which registered 6.6 on the Richter scale, or the April 2009 quake near L’Aquila, Italy, which measured 6.9—have occurred about 145 times per year since 2000.

In the past 100 years, quakes of all sizes have claimed nearly 2 million lives worldwide. The danger is now greater than ever, since the population has dramatically increased during the last two centuries. Some of the world’s most earthquake-prone regions are also the most densely populated.

The Pacific Rim has been the most volatile region, accounting for over 80 percent of the world’s largest earthquakes. In addition, several thousand small to moderate quakes occur each year around the west coast of North and South America—the eastern flank of the Pacific Rim. The southeastern Asian countries and many island nations are also in this volatile region. Japan alone is shaken by more than 1,500 seismic events (tremors or earthquakes) each year.

South America’s Andes Mountains formed when the ocean plate wedged beneath the continental plate and pushed it upward, forming the higher elevations. Catastrophic volcanoes shaped some of the mountain range, adding more landmass. By contrast, the trough beyond the South American shoreline is one of the deepest in the world (4,400 feet), due to the sunken Pacific plate!

Volatile Earthquakes

In Chile, a terrible series of earthquakes began high in the Andes on May 22, 1960. The following day, a quake registered 9.5 on the moment magnitude scale (explained later)—the highest reading ever recorded in the 20th century.

The rippling effects were enormous. New volcanoes and several older volcanoes suddenly activated. Islands disappeared off the coast. A 25-mile strip of the coastal mountains (about two to three miles wide) suddenly dropped 1,000 feet, finally wedging between two giant plates, now partially submerged in the Pacific Ocean. The resulting casualties reached over 1,600, as it struck several mountain and coastal villages.

The earthquakes generated seismic waves that sped across the Pacific at about 500 miles per hour. In some areas, 150-foot waves reached the shorelines. The main tsunami traveled more than 10,000 miles, wreaking havoc wherever it hit. Japanese authorities issued a tsunami warning in time to evacuate some of Japan’s shorelines, saving thousands of lives before the destructive waves hit 22 hours later. This was the first time a tsunami striking Southeast Asia originated as far away as South America.

The highest known tsunami waves reached 1,722 feet in Lituya Bay, Alaska, on July 10, 1968.

In 1883, a 120-foot tsunami hit the islands of northwestern Indonesia. This resulted from an explosive volcanic eruption that decimated the mountain island of Krakatoa, and erased all life from many small islands, taking more than 36,000 lives in Sumatra and Java alone.

Another tsunami hit the Philippines in 1976, killing over 5,000 people. Like most tsunamis, it too was caused by an earthquake.

The strongest earthquake recorded in North America centered near Anchorage, Alaska, in March 1964. It registered 8.5 on the Richter scale and 9.2 on the moment scale, and caused approximately 12,000 square miles of land southeast of Anchorage to rise about 7.5 feet. Roughly 35,000 square miles to the northwest dropped about five feet. Despite the enormous devastation, only 131 people died, since most damage occurred in sparsely populated areas.

In 1974, another quake of similar proportions could have been as lethal, but local farmers recognized that a well began yielding artesian water (water under sudden pressure)—one of the indicators of an imminent quake. The local populace sounded the warning, evacuating Haich’eng, China, and saving thousands of lives (Powers of Nature, Tom Melham).

Two years later, an earthquake in Guatemala resulted in 23,000 deaths and left a million homeless. That same year, the Tang Shan quake, near Peking, China, claimed an unbelievable 655,000 lives!

Measurement of Earthquakes

Dr. Charles Richter developed the Richter scale in 1935. While not a precise measure of earthquake energy, it provides a rough comparison of earthquakes. The scale is open-ended in that very small earthquakes may register as minus numbers, and no maximum limit exists. So far, no earthquakes have registered above the magnitude 9 range.

The Richter scale is logarithmic—meaning that for each unit jump (such as from 6.0 to 7.0 on the scale), the seismic wave amplitude increases 10 times, and the energy of the quake actually increases 30 times. This same comparison would apply from a 7.0 to an 8.0 on the scale—a 10-fold increase in seismic wave amplitude and a 30-fold increase in energy level. But from a 6.0 to 8.0, there would be a 100-fold increase in seismic amplitude and a 900-fold increase in energy level.

In a 1978 interview, Dr. Richter explained the scale, expressing his surprise that it worked as well as it did. He indicated that it was based on an assumption that could not possibly be true—that one could compare earthquakes merely by multiplying some arithmetical factor. He emphasized that two magnitude 6.5 tremors could release appreciably different amounts of energy (Powers of Nature).

Seismologists today generally use an improved and updated scale along with the Richter scale—the moment magnitude scale, which is determined by the area of a quake’s fissure and the displacement of the relative plates.

Using the moment magnitude scale (and comparing it to the Richter scale), the 1906 San Francisco quake measured 7.6 (8.3 on the Richter scale), 9.2 (8.5) for the 1964 Alaskan quake, and 7.0 (6.9) for the 1995 quake that struck Kobe, Japan. (Publications often differ regarding earthquake magnitudes, due to confusion as to which scale was used to report the quake.)

Devastating Tsunamis

The most devastating tsunami in modern history occurred on Dec. 26, 2004. An earthquake, registering 9.15 on the moment scale and with an epicenter on the ocean floor about 150 miles west of Sumatra, triggered a series of deadly waves just after dawn, pounding the island’s northwest coast. More than 180,000 were left dead or missing. However, Sumatra’s long span served to shield other Indonesian islands, the isthmus of Malaysia, and Singapore from imminent and cataclysmic disaster.

Primarily spreading toward the northern sectors of the Bay of Bengal, the tsunami dispersed east, north and west from the earthquake’s epicenter, striking 12 countries. Estimates of the dead and missing surpassed 250,000, making it one of history’s costliest natural disasters.

The tsunami affected the western shores of Thailand, where thousands of vacationers were visiting from around the world. Other countries that suffered loss included Myanmar (Burma), Bangladesh, the eastern shoreline of India and Sri Lanka.

In many areas, a second seismic wave proved to be more destructive, drowning thousands of injured and helpless victims who had narrowly survived the first wave.

Total destruction along the seacoasts was almost unparalleled in history—and all resulting from an earthquake that caused the seafloor to lift, and displace billions of tons of water. The PBS television program NOVA calculated that the resulting release of energy was equivalent to 23,000 Hiroshima sized atomic bombs! The earthquake that triggered the 2004 tsunami was the third most powerful ever recorded.

Nearly a year later, a major earthquake hit Pakistan (Oct. 8, 2005). Registering 7.6 on the moment magnitude scale, its epicenter was in the Kashmir region, a disputed territory that also borders Xinjiang, Tibet and India. By the end of 2005, the Pakistani government’s official death toll approached 90,000; other estimates exceed 100,000. Regions most affected were mountainous, where landslides blocked roads and impeded access. An estimated 3.3 million were left homeless, and relief efforts continued for months.

How God Uses Earthquakes

Earthquakes and volcanic activity have plagued man’s civilizations through history. Scripture declares that God will use earthquakes to punctuate climatic events in the near future.

Historically, the Creator has sometimes used earthquakes to demonstrate His presence (such as at Mt. Sinai, when ancient Israel received His laws), show deliverance from trials, express divine wrath, and indicate His unfolding Plan for humanity.

In addition, God’s Word, the Bible, states that He will use future earthquakes to accompany terrifying prophetic events, announce the Return of Jesus Christ, and reshape the earth’s surface.

To understand more, read our extensive prophetic trends and conditions report Earthquakes and Volcanoes in Prophecy.