Putting the science in fiction - Dan Koboldt, Chuck Wendig 2018
Earthquakes: fact vs. fiction
Earth and other planets. Yes, Pluto counts!
By Amy Mills
If there’s one type of natural disaster my home state of California is known for, it’s earthquakes. In 2017 alone there were more than 500 2.5-plus magnitude earthquakes in California, and more than 20,000 2.5-plus magnitude earthquakes in the world. The title of the largest earthquake of 2017 is held by an 8.2 magnitude earthquake off the coast of Mexico. That’s a lot of shaking.
Earthquakes were in the news for a few notable reasons recently: the movie San Andreas, an earthquake disaster movie released in 2015, an article in The New Yorker about the Cascadia Subduction Zone in the Pacific Northwest, and a devastating 7.3 magnitude Iran-Iraq earthquake that caused more than 500 casualties. Earthquakes are unpredictable, potentially deadly, and a great device in fiction to provide quick devastation and destruction.
The myths
To help you get earthquakes right, here are a few common misconceptions, and a couple tips, for writing earthquakes in fiction.
Myth #1: Earthquakes Can Be Predicted
Earthquakes are unpredictable. Natural disasters don’t have a “season.” They are a constant threat that can strike day or night, in the summer or winter. Despite extensive research on the subject, earthquakes cannot be predicted with sufficient precision to say what day an earthquake might hit, what month, or even what year. However, due to statistical analysis, scientists can provide long-term forecasts to give a likelihood of a large earthquake happening in the upcoming years. One of the most popular predictions of today is that a large earthquake, often cited as “The Big One,” is due to hit California in the next couple decades.
There is some level of prediction, however small. Many countries, including Mexico and Japan, do have earthquake early warning systems in place. These early warning systems can’t provide hours of warning, but they can provide precious seconds, enough time to get under something sturdy or get out of a building.
Myth #2: A Huge Earthquake on the San Andreas Fault Could Obliterate California
Not necessarily. While damage would be extensive and there would be loss of life when California’s most famous fault line rumbles, we probably wouldn’t be looking at a replication of the 1906 earthquake in San Francisco. California has some of the strictest building codes for earthquake safety in the United States. Though the state isn’t earthquake proof, measures have been put in place to limit the damage and/or loss of life. While the San Andreas is scary, scientists believe anything larger than an 8.3 magnitude earthquake is unlikely, and it wouldn’t be able to trigger a tsunami, either (tsunamis generally occur from earthquakes in subduction zones, which the San Andreas is not).
Myth #3: The Ground Will Split Apart
Sorry. Even if it does make a cool scene, the ground does not split open in an earthquake. Earthquakes are produced by faults slipping next to each other, not away from each other. No friction means no earthquake. Not to say there couldn’t be ground failures (landslides, spreads, cracks in sidewalks and asphalt), but there would be no gaping chasm in the street for your character to plunge to his death. Don’t worry! Soil liquefaction, which we’ll talk about later, can provide some pretty nasty devastation instead.
Myth #4: A Magnitude 7 Earthquake Behaves the Same Way in Any Part of the World
Sadly, no. The survivability in the aftermath of an earthquake can be highly dependent on building codes and emergency preparedness. Retrofitting existing buildings to bring them up to code can be expensive and infeasible for poorer countries. In some ways, it’s not about how strong the earthquake is but rather how safe the infrastructure is. This is why the damage and deaths from earthquakes can vary so greatly between countries even if they experience the same magnitude of earthquake. Not only that, but the timing of the earthquake could change everything. Consider the 1989 Loma Prieta earthquake in San Francisco. Despite the earthquake rattling San Francisco during rush hour, the casualties were relatively low. Why? Because the San Francisco Giants and the Oakland Athletics were in the World Series. Many residents were settling into watching the game—not driving on the roads.
What can you expect in an earthquake?
Depends on magnitude. Earthquakes are measured by magnitude on the Richter scale, which ranges from 0 to 10-plus. Magnitude is not as straightforward of a concept as some would think. The scale is logarithmic, so every additional step in magnitude is 10 times bigger than its predecessor. The points below generalize a range in magnitude and what the expected damage would be.
· 0 — 2.9 MAGNITUDE: This earthquake would not be felt.
· 3.0 — 3.9 MAGNITUDE: “Was that an earthquake?” This earthquake may be felt by an individual if she’s awake on an upper floor of a building, although she may not link the shaking with an earthquake. The rumbling would feel similar to a rumbling truck passing by.
· 4.0 — 4.9 MAGNITUDE: “We’re having an earthquake.” This earthquake would be strong enough to wake up an individual from sleep. Picture frames may crash on the ground and windows could break, but the damage is relatively low.
· 5.0 — 5.9 MAGNITUDE: “Duck and cover!” This earthquake would be strong enough to cause slight damage to well-built buildings and considerable damage to poorly designed structures. At this magnitude, the population would probably panic.
· 6.0 — 6.9 MAGNITUDE: “Hold on!” At this magnitude, an earthquake would cause considerable damage to a city. Furniture would be overturned and buildings may be tipped off their foundations. Throughout a city, monuments and statues would be toppled, and roads would be damaged.
· 7.0 + MAGNITUDE: “&#%!” Most masonry and wooden structures would be destroyed in this type of earthquake. Around a city, transportation would be severely disrupted as bridges could collapse, rails could be bent, and roads could be cracked. The city would be in chaos.
Earthquake side effects
Earthquakes in and of themselves are dangerous enough, but they can also trigger other disasters to make an earthquake situation that much deadlier. Here are four side effects of earthquakes that you can write into your fiction.
Soil Liquefaction
Soil liquefaction is the phenomenon where water-saturated soil strength is diminished by rapid loading. In nonscientific terms, when soil with high water content gets shaken—like by an earthquake—the soil turns into a liquid. Soil liquefaction is especially common near rivers, lakes, and beaches and can cause buildings to tip, their foundations sinking into the earth.
Infrastructure Collapse
I think this is everyone’s biggest fear in an earthquake—and with good reason. Buildings and bridges aren’t earthquake proof, and the scariest earthquake damage pictures are the ones with crumbled buildings. Building codes are designed to prevent collapse as much as possible, but nothing can prevent cracked concrete or falling debris. This is why it’s extremely important to duck and cover under something sturdy during an earthquake.
However, keep in mind if you’re writing futuristic SF that earthquake technology will only get better and better. Even now, there are some pretty awesome earthquake safety measures being utilized in bridges and buildings. For instance, some structures have been built on base isolators (flexible bearings that separate the foundation of the structure from the ground). The idea is similar to the suspension system in your car. A very expensive suspension system. In California, a few structures are already built (or were retrofitted) with base isolators. These include the San Diego-Coronado Bridge, Los Angeles City Hall, and the San Francisco-Oakland Bay Bridge. Japan, however, is the reigning leader of earthquake safety in infrastructure. The country utilizes base isolators, pendulums, and even giant curtains to help dampen the blow of an earthquake.
Tsunamis
Tsunamis are giant ocean waves triggered by underwater land disturbances, such as landslides, volcanic activity, or earthquakes. Tsunamis—in relation to earthquakes—occur only from earthquakes in underwater subduction zones (like the Cascadia Subduction Zone off the coast of the Pacific Northwest). If you want a tsunami in your fiction, make sure the earthquake happens in the water.
Utility Failures
The higher the magnitude of earthquake, the more likely key utilities will fail. Power lines, sewer lines, water lines, storm drain systems, gas lines—all can fail. This could mean sinkholes, gushing water from water main breaks, leaking sewage, destroyed cell phone towers, inability to process debit or credit card transactions due to lack of electricity, and no water or electricity for days or weeks or months. Broken gas lines and downed electrical lines can spark fires, which caused much of the property damage in the 1906 San Francisco earthquake. In fiction, it’s important to address these side effects of a massive earthquake, as they’ll cause most of the problems post-earthquake.
There you go! A few misconceptions and facts about earthquakes. As a friendly PSA, make sure you have an emergency plan in case there is an earthquake in your area. And if the ground does start moving, remember to get under something sturdy, cover your head, and hold on.