In recent decades, engineers and architects have learned a lot about how to make structures more impervious to earthquakes. New materials and designs have been introduced to make buildings better equipped for future earthquakes to come.
However, there are delays in building authorities adopting these newly developed materials due to inertia in some of the most earthquake-prone regions. In California, for example, a strong quake hadn’t happened since the 1994’s Northridge quake in Los Angeles until the Ridgecrest quake in July 2019 some might argue it’s been, since 1906, when a powerful temblor nearly decimated San Francisco.
So instead of clamoring for better technology or insisting their residence, workplace, school or hospital be better engineered for impending threats, residents in these areas might be satisfied with the older safety standards offering the bare minimum of earthquake preparedness. That’s especially true in the case of stronger quakes.
The fact that Oklahoma had some of the highest numbers for earthquakes from 2010 to 2015, according to the U.S. Geological Survey (USGS), may surprise some people. The state recorded 888 earthquakes in 2015 as opposed to California, which is considered earthquake central, and had just 130 quakes. Alaska had more earthquakes than both Oklahoma and California combined, experiencing 9,020 during the six-year stretch.
Of course, not all earthquakes are created equal. Some seismic activity occurs deep in the earth’s surface where only the most sensitive equipment can detect it. Others, like the ones in California, have massive, open scars on the surface indicating major earthquake faults.
Nonetheless, California’s seismic engineering and construction requirements are designed to protect the lives of those inside buildings. Even with the most modern codes, building to the state’s minimum requirements could leave even new buildings severely damaged in a major earthquake – to the point of being a complete loss.
Earthquake experts are becoming increasingly concerned about this, noting that a massive temblor would leave many without homes and offices for months if not years.
How Are High-Risk Seismic Activity Areas Targeted?
Seismologists work to determine risk in two ways: earthquake predictions and earthquake forecasting.
1. Earthquake Predictions
Earthquake predictions focus on the risk of an event itself. Testing is difficult but seismologists use heuristically derived advanced algorithms to predict earthquakes. They also look at seismic patterns in the area. Just as importantly, they monitor the indigenous wildlife in the region such as the common toad. At least one study found that toads will run days before an earthquake strikes.
2. Earthquake Forecasting
The science is not exact and the earth’s crust is too large for it to be completely accurate. Earthquake forecasting concerns itself more with the frequency and potential magnitude of damaging earthquakes in an area.
When looking at specific regions, scientists will also take into account seismic hazards such as landslides or tsunamis and seismic risks like potential economic loss and casualties should an earthquake hit. Modern earthquake structural engineering can reduce the seismic risks in an area even though it has a real chance of experiencing an earthquake.
Top Areas in the U.S. with the Biggest Seismic Risk
For centuries, seismic specialists have watched key faults like the San Andreas that runs through California. They continually look for signs of stress on the fault. Let’s look at some other areas that offer present the biggest concerns.
San Andreas Fault
The San Andreas Fault is one of the most talked-about risk zones, in part because of the cities around it like Los Angeles and San Francisco. There is little question that the San Andreas will produce a major earthquake in the not too distant future.
This fault sits between the Pacific and the North American tectonic plates and is believed to have formed more than 30 million years ago. In 1857, it produced an earthquake measuring 7.9 on the Richter scale. It was also behind the 1906 San Francisco earthquake that killed 3,000 people. It’s hard to say when the next quake will hit but one study by the USGS predicts it will be at least a 7.8 and could cause 213 billion dollars in damage.
Cascadia Subduction Zone
It’s been over 300 years since there has been any real activity along this zone which runs from Vancouver Island to Northern California. It’s known to have the potential to produce up to a 10.0 magnitude earthquake that could affect major cities such as Seattle, Portland and Vancouver.
New Madrid Seismic Zone
The New Madrid Seismic Zone gets its name from New Madrid, Missouri, the fault’s starting point. In 1811, it produced a series of earthquakes including its first on December 16. It was a 7.5 to 7.9 magnitude quake followed quickly by a 7.4 aftershock. In 1968, the residents of Dale, Illinois reported a 5.4 quake felt in 23 different southern states including in Henderson, Kentucky where it destroyed the city’s civic building.
Of the current active faults, this one is causing the most concern. Scientists are predicting that a major quake along this fault could damage areas in 11 states and lead to as many as 4,000 deaths.
The Wasatch Fault lies right under the City of Salt Lake and the urban corridor of Utah, home to around 1.6 million people. The first quake was felt by Mormon settlers in 1847 and there has been little activity since then.
Earthquake specialists say don’t let the lack of shaking fool you. They predict this fault can produce at least a 7.5 magnitude earthquake in a very crowded area of the country. In addition, the fault has distinct segments that move independently of one another, making it a natural force to be feared.
Ramapo Fault System
This fault runs through Pennsylvania, New Jersey and New York. In fact, the last group of residents to experience a quake from Ramapo lived in Brooklyn. The biggest danger here is the location. Even a smaller quake along this fault could cause widespread property damage. It’s not an area where people plan ahead for earthquakes. Many of the structures are historic and not able to withstand the shaking.
It’s nearly impossible to know where the next major earthquake will hit. What is known is that some regions of the country have not developed earthquake resistant buildings to handle one, and are not taking steps to safeguard the public seen more recently in California and Alaska. In these other regions not generally associated with earthquake disasters, infrastructure may crumple and buildings may topple, taking residents totally by surprise.
Thankfully, these areas can learn from the negative impacts that have followed earthquakes in other, more active regions and can still take steps towards mitigating the dangers that come with seismic events. By investing in earthquake-resistant infrastructure, cities, communities and business owners can ensure they are as well-prepared as possible for disaster, when –– not if –– it strikes.
Optimum Seismic is one of the most qualified companies for earthquake retrofitting in Los Angeles. Our experienced team has been making cities safer since 1984 by performing earthquake engineering to achieve earthquake resistant buildings. Our full-service seismic retrofit engineering and construction services cover multifamily, residential, commercial and industrial buildings throughout the state of California. If you have a multifamily, residential, commercial, or industrial building that needs to be brought up to current earthquake codes, call us today at 833.978.7664 or request a free estimate and one of our seismic retrofit experts will reach out to you directly.