Key Takeaways

• According to a report from Statista, the United States experienced a total of 43 major natural disasters in the year 2021, which was by far the highest number reported globally.
• Sean Potter, who is an NYC-based weather historian and meteorologist, states, "The contrast of cold, dry, Arctic air from Canada and warm, moist, tropical air from the Gulf of Mexico, Pacific and Atlantic help fuel the massive storms that move across the country year-round, bringing everything from blizzards to heavy rain and thunderstorms, depending on the time of year."
• North America lacks an east-west mountain range, which means there are no structures to block cold winds traveling from the north that eventually collide with warm weather in the south, leading to weather extremes.
• In the United States, low-pressure systems typically extract cool and dry air from the High Desert (southwest) or the Rocky Mountains, while extracting the humid and warm air from the Gulf of Mexico. Those areas that lie in between these regions then become the perfect breeding ground for severe weather. Furthermore, almost one-third of the United States consists of the Mississippi River valley and the Great Plains, croplands and grasslands that rapidly heat up and develop "pockets of rising warm air."

Introduction

The U.S. Has the Highest Number of Disasters

• According to a report from Statista, the United States experienced a total of 43 major natural disasters in the year 2021, which was by far the highest number reported globally. Indonesia was second, having reported 28 natural disasters in 2021, followed by India and China with around 19 and 17 respectively.
•  Over 2,000 natural disasters have been recorded in the United States over the last seven decades, according to World Atlas. The 20 different billion-dollar disasters (those causing in excess of $1 billion in damage) in 2021 alone accounted for more than $152.6 billion in costs. Indirect and direct fatalities from these billion-dollar disasters amounted to at least 724 in 2021, which was twice as large as the number reported for the previous year and the sixth largest on record.

 

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• The majority of these major natural disasters reported in the United States in 2021 were severe storms, followed by tropical cyclones. Also, billion-dollar natural events have accounted for $2.15 trillion of the $2.5 trillion (or 85%) in disaster-related costs in the United States from 1980-2021.

 

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Reasons

1. Geographic Makeup/Diversity

• One of the primary reasons why the United States experiences the highest number of natural disasters is the geographic makeup/diversity of the country, which indicates that some areas of the country are more prone to certain types of natural disasters when compared to others. Each of the nation's geographic regions experiences "a unique combination of weather and climate hazards", as reported by the National Centers for Environmental Information (NCEI).
• The country is positioned between two separate oceans and the mid-latitudes, meaning that the nation is situated between the North Pole and the equator. Sean Potter, who is an NYC-based weather historian and meteorologist, states, "The contrast of cold, dry, Arctic air from Canada and warm, moist, tropical air from the Gulf of Mexico, Pacific and Atlantic help fuel the massive storms that move across the country year-round, bringing everything from blizzards to heavy rain and thunderstorms, depending on the time of year."
• Moreover, North America lacks an east-west mountain range, which means there are no structures to block cold winds traveling from the north that eventually collide with warm weather in the south, leading to weather extremes.
• All regions of the United States are at some degree of risk from severe storms and tornadoes. Interestingly, the country reports between 80% and 90% of all of the planet's tornadoes.
• In states in the Southwest and near the Pacific Coast, citizens are affected by hurricanes and tropical storms forming in the eastern Pacific Ocean, the Caribbean Sea, the southern Atlantic Ocean, and the Gulf of Mexico. While floods can occur anywhere throughout the United States, states in coastal areas are more prone to them due to the impact of the hurricane season.
• Similarly, earthquakes can take place in any state. However, those near active fault lines, such as the states of California, Nevada, Washington, and Hawaii, have a higher frequency of this particular natural disaster.
• To illustrate the geographic breakdown described above, in 2021, billion-dollar natural disasters that the United States experienced included eight severe weather events, four tropical cyclones, three tornado outbreaks, two flood events (in Louisiana and California), one winter storm/cold wave (in Texas and the deep south), one wildfire "event" (wildfires reported across seven different states), and one drought/heatwave event (in the western portion of the country).

 

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2. Climate/Atmosphere of Southern and Midwest States

• Another reason why the United States reports more natural disasters than other nations concerns the climate and atmospheric conditions of the states situated in the Midwest, South, and the Plains.
• In the United States, low-pressure systems typically extract cool and dry air from the High Desert (southwest) or the Rocky Mountains, while extracting the humid and warm air from the Gulf of Mexico. Those areas that lie in between these regions then become the perfect breeding ground for severe weather. Furthermore, almost one-third of the United States consists of the Mississippi River valley and the Great Plains, croplands and grasslands that rapidly heat up and develop "pockets of rising warm air."

 

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• As stated by Dr. Harold Brooks, an NOAA National Severe Storms Laboratory senior scientist, severe thunderstorms that produce tornadoes merely require cool, dry air at between 10,000-30,000 feet and humid, warm air close to the ground, along with horizontal winds.
• Referring to the uniqueness of the topography and atmospheric conditions in southern states, Dr. Brooks goes on to state, "No place else in the world has the large warm water on its equatorward side with a wide high range of mountains extending from north to south to the west of it."
• As a result, the United States experiences twice as many thunderstorms as Europe. It also recorded a much larger yearly average tornado count from 2011-2020 (1,173 vs. 256) despite being similar in size.

 

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3. Climate Change

• Finally, researchers believe that climate change and human-caused global warming have helped to exacerbate the frequency and severity of natural disasters in the United States and worldwide, although this belief is not universal. Climate change is actively impacting regional temperatures in the country and is expected to worsen the impact of such disasters.
• Moreover, human-caused global warming has caused a rise in sea surface temperatures in the Atlantic, which much of the East Coast is exposed to, along with causing atmospheric circulation shifts that encourage the formation of tropical cyclones.

 

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• In their research study titled Tropical Cyclone Frequency Under Varying SSTs in Aquaplanet Simulations (published in February 2021), hurricane scientist Adam C. Burnett, along with three colleagues, found that Intertropical Convergence Zones (ITCZ), which are globe-encircling heavy thunderstorms, are shifting poleward, increasing the volume of named storms in the Atlantic. The study acknowledges the possibility that human-caused global warming has caused such shifts.
• The frequency of natural disasters can be connected to climate change, according to Paul Ullrich, a UC Davis associate professor of regional climate modeling. Increased intensity of land-falling storms in the United States over the years has resulted in greater precipitation, and warmer air can hold additional water vapor, leading to extreme precipitation events (e.g., hurricanes and tornadoes). In turn, these developments lead to greater precipitation themselves, causing floods.
• Additionally, some states have endured stronger summertime drying due to hotter temperatures recorded during the summer season, mixed with the melting of snowpacks in the Upland forests and the Sierra Nevada. In California, there has been an erosion of 20%-30% of natural mountain snowpack over the past five decades because of climate change, resulting in drier conditions because of the limited amount of snow. This has caused forests to dry and increased the likelihood of wildfires.
• In Texas, a stratospheric sudden warming event recently enabled Arctic air to escape from the Arctic circle southward and travel to the southern portion of the state. After the air escaped, there was "no correcting factor from the underlying meteorology" that was capable of confining it, leading to a prolonged effect on local weather patterns, most notably a confounding Texas winter in which temperatures fell to 20 degrees in the city of Houston in mid-February (56 degrees is the average temperature during this time).

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Key Takeaways

• The U.S. Geological Survey, the “sole science agency for the Department of the Interior that is sought out by thousands of partners and customers for its natural science expertise”, categorically states that California will stand in the event of a major earthquake.
• A 2022 study looked into the San Andreas Fault and found that over 100 earthquakes had resulted from the Fault. With every quake, the Fault is believed to have “jumped” more than 5 feet, or 1.5 meters. With these figures in mind, the study extrapolates that the “Big One” could result, at the very least, in a magnitude 6.9 earthquake.
• Seismologists John Vidale and John Wallace agree that the “Big One” could take about 1,800 lives and leave more than 50,000 injured. While collapsed structures and falling debris would result in many deaths, they believe that the highest cause of death would be fire. “Historically, the biggest hazard from earthquakes has been fire. In the 1906 earthquake there were 3,000 or 4,000 people who were just caught in that wave of fire that swept through the city,” Vidale says.
• The U.S. Geological Survey predicts that there is a 31% chance that a 7.5-magnitude (possibly the "Big One") will hit the Los Angeles area in the next 30 years. For San Francisco, the chance of a similar-sized earthquake hitting the Bay area in the next 30 years is 20%.

Introduction

The Threat of the “Big One”

• The Columbia Climate School states that the threat of a major earthquake, dubbed the "Big One" in California is “legion”. It describes the San Andreas Fault as an “800-mile-long monster” that divides California from South to North.

• According to the article, geologists describe the build-up to this massive earthquake as follows, “The San Andreas Fault comprises three major sections that can move independently. In all three, the plates are trying to move past each other in opposing directions, like two hands rubbing against each other. In the southern and the northern sections, the plates are locked much of the time—stuck together in a dangerous, immobile embrace. This causes stresses to build over years, decades or centuries. Finally, a breaking point comes; the two sides lurch past each other violently, and there is an earthquake”. In the central section that separates the first 2 sections, Columbia Climate School states that the plates slide past each other “at a pleasant, steady 26 millimeters” annually, resulting in no stresses and no subsequent earthquakes. This is referred to as an aseismic creep.

 

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• A 2022 study by Genevieve Coffey, Heather Savage, and 5 more authors looked into the San Andreas Fault and found that over 100 earthquakes had resulted from the Fault. With every quake, the Fault is believed to have “jumped” more than 5 feet, or 1.5 meters. With these figures in mind, the researchers extrapolate that the “Big One” could result, at the very least, in a magnitude 6.9 earthquake. “But many could well have been larger because the method of estimating earthquake magnitude is still evolving,” according to researchers.

• “People should not be alarmed. Building codes in California are now quite good. Seismic events are inevitable. Work like this helps us figure out what is the biggest possible event, and helps everyone prepare,” says study co-author and Columbia University’s Lamont-Doherty Earth Observatory geologist Stephen Cox.

• How Stuff Works, a website that offers “explanations of how the world actually works”, believes the magnitude of the “Big One” will be 8.0 and higher but does not think it would result in any separation. “But while the Big One would definitely wreak mass destruction, it would not sink part of California into the ocean, nor would it break the state off from the rest of the country,” the article asserts.

• Both John Vidale, a seismologist, and Dr. Thomas Jordan, a Professor of Earth Sciences at the University of Southern California and former director at the Southern California Earthquake Center agree that despite popular belief, the “Big One” would not cause a tsunami like the one that hit Japan, or trigger any separation.
• In a 2015 interview with the Smithsonian Magazine, Dr. Jordan posits, “The really big tsunamis, like the one that hit Japan, are caused by earthquakes that generate a major displacement of the ocean floor. The San Andreas fault sits far inland, and the land slips past on either side. For that reason, a quake also can’t cause the fault to split apart into a giant chasm as it does in the San Andreas film”. The last bit refers to a 2015 movie titled San Andreas, which depicts the “Big One”, whose effects included a tsunami.

• The U.S. Geological Survey, the “sole science agency for the Department of the Interior that is sought out by thousands of partners and customers for its natural science expertise”, categorically states that California will stand in the event of a major earthquake. It explains, “California is not going to fall into the ocean. California is firmly planted on the top of the earth’s crust in a location where it spans two tectonic plates. The San Andreas Fault System, which crosses California from the Salton Sea in the south to Cape Mendocino in the north, is the boundary between the Pacific Plate (that includes the Pacific Ocean) and the North American Plate (that includes North America). These two plates are moving horizontally, slowly sliding past one another. The Pacific Plate is moving northwest with respect to the North American Plate at approximately 46 millimeters per year (the rate your fingernails grow). The strike-slip earthquakes on the San Andreas Fault are a result of this plate motion. There is nowhere for California to fall, however, Los Angeles and San Francisco will one day be adjacent to one another!”

Worst-Case Scenarios

• The Smithsonian Magazine also believes that the “Big One”, should it ever happen, would result in over $200 billion in damage, 2,000 deaths, and over 50,000 casualties.

• In a 2019 interview with Business Insider, seismologists John Vidale and John Wallace agree that the “Big One” could take about 1,800 lives and leave more than 50,000 injured. While collapsed structures and falling debris would result in many deaths, they believe that the highest cause of death would be fire. “Historically, the biggest hazard from earthquakes has been fire. In the 1906 earthquake there were 3,000 or 4,000 people who were just caught in that wave of fire that swept through the city,” John Vidale says.

• Vidale, Wallace, and 2 other experts interviewed by Business Insider also add that there will be massive damage to the infrastructure and economy of California should a high-magnitude earthquake hit. Wallace narrates, “The San Andreas will produce the kind of long-period shaking which would be very damaging to very tall buildings, say, in downtown LA, and Century City, and Long Beach, and so forth. For older steel buildings, the connections in them have not necessarily been designed to withstand the maximum forces that actually can be generated. The number of buildings that were constructed before about 1980 is really significant, and most of these buildings are very vulnerable to damage and collapse.”
• Scott Brandenburg adds, “ Below our streets and our buildings is this really complicated network of infrastructure that could be damaged, and a lot of the things we take for granted every day won't be available anymore, right? Like water, electricity, being able to drive where you need to drive.”

• The article also highlights the possible damage to gas and oil pipelines, citing that the San Andreas Fault intersects with 39 such pipelines. A high-magnitude earthquake could break open gas lines, leading to “deadly explosions”.

• Touching on the effect of the “Big One” on access to clean water, John Stewart, another expert included in the Business Insider interview states, “So we would be without the lifelines that bring in imported water to the region. They cross through tunnels, cross through aqueducts near the surface. All of these would be ruptured, and so we would be losing 60% of our water supply. Many of these distribution lines for water are near sewer lines, which would also be broken, so now you have a situation where contaminants are potentially getting into the water supply”.

Origins of the Idea and Predictions on California’s Seismic Activity

• Articles by the Smithsonian Magazine and Business Insider insinuate that “catastrophic earthquake scenarios” like those depicted about the “Big One” are sensationalized by movies.
• According to Curbed Los Angeles, as of 2018, there were eight movies that showed the destruction of Los Angeles by geologic events, including "Earthquake" (1974), "The Great Los Angeles Earthquake" (1990), and "San Andreas" (2015). The author noted that LA-based moviemakers were particularly likely to depict catastrophic scenarios for their hometown.

• How Stuff Works believes, “The idea comes from a misunderstanding of the seismic forces that cause earthquakes in the region”.

• Another report by the U.S. Geological Survey predicts that there is a 31% chance that a 7.5-magnitude (possibly the "Big One") will hit the Los Angeles area in the next 30 years. For San Francisco, the chance of a similar-sized earthquake hitting the Bay area in the next 30 years is 20%. The report does state, however, that in the same time frame, there is a 60% and 72% chance that a 6.7-magnitude earthquake will hit Los Angeles and the San Francisco Bay area respectively.

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