Speaking of extinction-level events, did you hear that the Pacific Ring of Fire is ablaze with 69 earthquakes, 16 of them measuring 4.5 or more on the Richter scale of severity, within the past 48 hours, as reported by the U.S. Geological Survey?
In breaking news, a series of earthquakes that lie along the continental plate faults that rim the Pacific Ocean region have suddenly and in rapid succession begun shaking the Earth. With 452 volcanoes (that’s more than 75 percent of all volcanoes, active and dormant), this Ring of Fire comprises oceanic trenches, volcanic arcs and belts, and tectonic plate shifting of the Earth’s crust or surface.
The Ring of Fire is a vast area. It goes “from New Zealand, all around the east coast of Asia, over to Canada and the USA and all the way down to the southern tip of South America and causes more than 90 percent of the world’s earthquakes.”
In the past two days, Indonesia felt seven significant earthquakes. Single quakes shook the Soloman Islands, Bolivia, and Tonga.
To understand the magnitude, literally, of earthquake measurement, the Richter scale, named in the 1930s by its inventor Dr. Charles Richter, ranges from 1 (the smallest) to 10 (the largest). Before Richter introduced scientific instruments capable of recording seismic waves, tremor strength was guestimated subjectively by direct observation of the ground shaking.
In 1935, Dr. Richter proposed building sensing devices that would measure results in a mathematical scale called logarithmic rather than linear. In linear base-10 math, counting from 1 to 2 increases the amount by one. In log-10, as used by the Richter scale, an increase from 1 to 2 means ten times as much! In other words, a magnitude 8 earthquake (8M) is ten times as intense as a 7M trembler.
“In terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released, and each increase of 0.2 corresponds to approximately a doubling of the energy released,” according to Wikipedia.
It takes a quake of 4M to cause objects to fall off shelves indoors. At 5M, shaky buildings fall down. 6M tremors begin to inflict more significant damage, even to structures designed for resistance. At 7M, most buildings will tumble; 8M will destroy structures in large areas; and 9M and above means permanent changes to the landscape and complete or nearly total destruction of all buildings, earthquake-resistant or not.
You’ll note that the Ring of Fire includes parts of the USA. California, Oregon, and Washington are all situated atop the Cascadia subduction zone, where one tectonic plate moves under a neighboring one, pulling the earth down. The Cascadia subduction zone stretches from Northern California to British Columbia, Canada.
Better known is the San Andreas Fault, located to the south, “a sliding boundary between the Pacific Plate and the North American Plate. It slices California in two from Cape Mendocino to the Mexican border. San Diego, Los Angeles, and Big Sur are on the Pacific Plate. San Francisco, Sacramento and the Sierra Nevada are on the North American Plate.”
Thanks to its location on the Cascadia subduction zone, Washington residents keep an eye on their Mt. Rainier in case it decides to go all Mt. Saint Helens on them. (Mt. St. Helens, also in Washington, erupted on May 18, 1980, and killed 57 people in “the largest and most destructive volcanic eruption in U.S. history.”)
Although California has five active volcanoes, the state is more famous for its earthquakes. The most recent activity occurred last May (2018) when a 4.5M temblor struck near San Diego in the south and, 18 hours later, a second 4.5M quake was recorded off-shore in the northern part of the state.
Earthquake experts agree that California is overdue for a massive, catastrophic, earth-shaking episode. Colorado State University Geophysics professor Richard Aster maintained that: “For major events, with magnitudes of seven or greater, California is actually in an earthquake drought.”
So the question on many people’s minds today is:
Could this heightened volcanic activity in the Rim of Fire foreshadow “The Big One,” a quake that registers 8.0 or higher on the Richter scale and wreaks total devastation on major West Coast populations? For many years, the notion has been bandied about that a sizeable quake could – and ultimately, will – split off California, dividing it along the San Andreas Fault, sending it sliding down, into the Pacific Ocean, to be subsumed under the salty waves.
In fact, a full rupture along the 650-mile-long offshore Cascadia fault could trigger a 9.0 magnitude earthquake and companion tsunami.
Now you know why people are sitting up and taking notice that a magnitude 8.2 earthquake was detected in the Pacific Ocean close to Fiji and Tonga. Luckily, it was too deep to cause any pronounced damage. But what’s going on now, seismically, in the western United States?
In late July, quakes ranging from 2.8M to 5.6M were detected off the west coast of the United States “on the seabed of the Juan de Fuca tectonic plate, approximately 6 miles below the surface,” as reported by the Fox News in the New York Post.
According to Earthquake Track, yesterday (August 21, 2018) a 6.2M earthquake was recorded near coastal Bandon, Oregon.
Could the Big One be just around the corner? Will it be “curtains” for large swaths of the western U.S. seaboard? Let us all hope and pray it won’t come to that – while preparing for worst possible outcomes.