Earthquake Preparedness: Can Being Ready for One Disaster Better Prepare Us for Another?

Posted Wed, 10/28/2020 - 15:24
By Savannah Turner, Office of Response and Restoration

Philosophers, spiritual leaders, poets, novelists, and a variety of other historical thinkers have long attempted to define the concept of wisdom. Research on the subject alludes to the wise as being decision makers who tend to possess humility, strong cognitive capacity, reflection and compassion. I am grateful for the sage in my life, my grandmother, who at 96 years old continues to be one of the most resilient individuals I have ever known. She has always said that being ready for one kind of disaster will inadvertently help us be better prepared for another. I think that adage is relevant for us all, regardless of whether you live in the Gulf and focus on hurricane preparedness, or live along the Cascadia subduction zone in Washington state. 

My grandmother lived through the great depression, World War II, numerous hurricanes, earthquakes, the eradication of smallpox and polio, and enjoyed a 45 year marriage to a Naval explosive ordnance disposal officer. The wisdom she gathered and continues to pass on to her posterity most often comes in the form of a story, or personal experience that belies a lesson tailored to guide a preferred behavior or decision. In a more contemporary context, this blog similarly endeavors to provide traditional knowledge or wisdom aimed toward disaster risk reduction during an earthquake.

Similar to the lessons learned that are passed down from generation to generation, the ground beneath our feet has a sense of permanence. This foundation is easy to take for granted because the mountain ranges, oceans, and landscapes seem all enduring when compared to the human lifespan. However, these fixtures can change dramatically in an instant. Where high-severity wildfire can hinder the ability of an ecosystem to recover, so too can a major earthquake significantly alter topography.

Earthquake damage — a crack in a road.
Infrastructure damage from a magnitude 7.0 earthquake in Anchorage, Alaska in 2018. Image credit: USGS.

Why do Earthquakes Occur?

Most of us give little actual thought to the fact that thousands of small earthquakes, also called temblors, occur daily all over the world. We seldom feel these small tremors as we move about our busy lives. Most earthquakes occur along the fault line, or intersection of tectonic plates. These mammoth slabs of the earth’s upper crust meet and move against each other, riding the partially molten layer of Earth’s mantle. However, these movements can be powerful enough to cause deep cracks where the plates meet and, in unstable zones, the intensifying pressure can ultimately trigger an earthquake. 

The factors that result in significant seismic events are quite varied and difficult to predict. Different fault lines contain different kinds of rocks, some stronger and some weaker. These rocks also react differently to friction and high temperatures. Some can melt, but others remain dry and can be prone to build up dangerous levels of pressure. All of these fault lines are also subject to varying degrees of both gravitational forces and the current of molten rock moving under the Earth’s crust. 

We measure the magnitude of an earthquake by the strength and duration of its seismic waves. An earthquake that measures 3 to 4.9 is considered minor or light; 5 to 6.9 is moderate to strong; 7 to 7.9 is major; and 8 or more is great. While earthquakes can occur anywhere without warning, the highest risk areas for earthquakes in the United States include Alaska, California, Hawaii, Oregon, Puerto Rico, Washington and the Mississippi River Valley.

Earthquake Preparedness and Lessons Learned 

So what should we be prepared for, or concerned about? Is it really the magnitude of the earthquake that poses the greatest threat, or does infrastructure, proximity to water, or expectation (high risk areas) play a larger factor? The answer is not a definitive one, but the Disaster Preparedness Program believes we can learn from others in this regard. Take the magnitude 8.8 earthquake that occurred off of the coast of south-central Chile on February 27th, 2010. This earthquake caused three minutes of intense shaking which resulted in widespread damage on land and initiated a tsunami that impacted coastal areas of the country. Together, the earthquake and tsunami were responsible for more than 500 deaths. This Chilean earthquake was significantly larger than the one that occurred only a month prior in Haiti, but did not cause nearly as many lives to be lost. The magnitude 7.0 Haitian earthquake in January of 2010 resulted in approximately 160-220 thousand deaths. Earthquakes alone do not cause high numbers of casualties, the resulting collapse of buildings, bridges, dams, fires resulting from ruptured gas lines, or cholera can be much more deadly.

Earthquake damage.
Damage to structures in downtown Concepcion, Chile, due to the February 27, 2010 magnitude 8.8 earthquake. Image Credit: Walter Mooney, USGS.

Chile has long passed down warnings and stories of the devastation earthquakes can cause. One of the largest earthquakes ever recorded, a magnitude 9.5 occurred in Chile in 1960. One simply has to look at the changes Chile made to their building codes to ensure more earthquake resilient infrastructure to know that these warnings were heeded. Chileans also knew to expect earthquakes and were better prepared as a result. Unfortunately, Haiti did not have the same history, resources, or expectation. The 2010 Haitian earthquake occurred along a blind fault line. They did not know it existed. The fault line in Chile is well known and earthquakes occur frequently along the fault line. Even the surrounding countries are aware of that threat and prepare for the threat of a tsunami given the frequency earthquakes have occurred in the area. 

So what is the lesson here? What can we learn from those with wisdom gained through experience? We have to respect the reality of the threat and prepare for the possibility that a “big one” could occur any moment, and in unsuspecting places. We have to educate those we care about. Learning to accurately predict and prepare for earthquakes is a long game. Work continues to identify precursor earthquakes that may provide an indication for days to minutes of warning. However, even today, most of our clues come from long-term forecasting, which is based on when and where earthquakes have previously occurred. This allows us to make very loose predictions about when highly active faults, like the San Andreas, are overdue for a massive earthquake.

Given the fact that earthquakes can be unpredictable, we have to prepare in advance. Many of the same measures we implement for other disasters are applicable for earthquakes, such as putting together an emergency kit and plan. Per Ready.gov, here are some suggestions you can take to prepare for an earthquake:

  • Create a family emergency communications plan that has an out-of-state contact

  • Plan where to meet your family if you get separated 

  • Make a supply kit that includes enough food and water for several days, a flashlight, a fire extinguisher and a whistle

  • Assess your home for some of the easier improvements you can make, such as securing heavy items in bookcases and objects that hang on walls 

  • Store heavy and breakable objects on low shelves 

  • Assess homes and buildings for structural issues that could cause a collapse during an earthquake

  • Practice Drop, Cover, and Hold On with your family and coworkers. 

A graphic depicting "drop, cover, and hold on."
Protect yourself during earthquakes. Image credit: Department of Homeland Security.

Stay Safe During an Earthquake

If you feel the building you are in start to shake, wherever you are, drop down to your hands and knees and hold onto something sturdy. If you’re using a wheelchair or walker with a seat, make sure your wheels are locked and remain seated until the shaking stops. Cover your head and neck with your arms. If a sturdy table or desk is nearby, crawl underneath it for shelter. If no shelter is nearby, crawl next to an interior wall (away from windows). Crawl only if you can reach better cover without going through an area with more debris. Stay on your knees or bent over to protect vital organs. If you are under a table or desk, hold on with one hand and be ready to move with it if it moves. If seated and unable to drop to the floor, bend forward, cover your head with your arms and hold on to your neck with both hands. 

If you are outside, find an open area and drop to the ground. Stay there until the shaking stops. Try to get as far away from buildings, power lines, trees, and streetlights as possible. If you're in a vehicle, pull over to a clear location and stop. Avoid bridges, overpasses and power lines if possible. Stay inside with your seatbelt fastened until the shaking stops. Expect aftershocks to occur. Be prepared to drop, cover and hold if you feel an aftershock. After an earthquake, there can be serious hazards such as damage to the building, leaking gas and water lines, or downed power lines. If you are in a damaged building, go outside and quickly move away from the building. Do not enter damaged buildings.

These are simply a few measures to familiarize yourself and your family with, regardless of whether you live in a high risk area. We have more knowledge of risk and information at our fingertips than my grandmother ever had. We should prepare for the unknown by studying how others in the past have coped with the unforeseeable and the unpredictable. 

The Disaster Preparedness Program recommends taking a moment to learn from the wise and review additional earthquake preparedness measures from sites like Ready.gov or the American Red Cross site on earthquake safety.