The Big Ones: How Natural Disasters Have Shaped Us (and What We Can Do About Them)

by Lucy Jones

Earthquakes are happening constantly around the world. The seismic network that measures earthquakes in Southern California, where I live and spent my career as a seismologist, has an alarm built into it that goes off if no earthquake has been recorded for twelve hours—because that must mean there’s a malfunction in the recording system. Since the network was put into effect in the 1990s, Southern California has never gone more than twelve hours without an earthquake.

Because we live on land, we tend to make an existential distinction between what appears at the surface and what is submerged beneath our rivers, lakes, and oceans. But a river is not fundamentally different from the land around it. There is no distinction in the types of earth that form the riverbanks, nothing unique about the crust that lies beneath it. It is simply lower lying than the areas around it. Water flows down to wherever gravity pulls it, so, inevitably, bodies of water form at those areas of lower elevation. This is stating the obvious, but it’s a truth we tend to lose sight of. The Mississippi River is where it is because the land beneath it is at a lower elevation than nearly all the land surrounding it. In fact, for the last 450 miles of the Mississippi, the riverbed is actually below sea level. (As it approaches New Orleans, the bed of the Mississippi is as low as 170 feet below sea level.) The upper parts of the water continue downhill and with friction pull the rest of the water with them. It makes for a turbulent passage.

The second mind shift we need to make is to realize that a river is not just water. Moving water has the energy to carry many things within it. Naturally, the smaller and lighter the object, the easier it is to carry, and the faster the water is moving, the more it can propel. It’s no accident that the Mississippi’s nickname is the Big Muddy. Like all rivers, it picks up grains of sand and dirt with its motion, carrying them in suspension into the ocean. When the water slows down, it drops some of that sediment, with the bigger and heavier grains being deposited first.

the risk the levees faced was twofold—the pressure of the river and the malevolence of the humans in their vicinity. The confined river put immense pressure on levees, and an at-risk town’s best defense could be to sabotage the levee on the other side of the river. Once one side failed, the pressure on the other was eased. So, in a real-life prisoner’s dilemma, a community that was threatened and had the means, the desperation, and the shamelessness could stay safe by putting its neighbors underwater.

The evolution of human history might be seen as a gradual expansion of the concept of personhood, from identifying with one’s own tribe, to the development of the concept of a nation, to an expanding acceptance of the larger world. You don’t have to look far into these examples, or into today’s news, to recognize that we still have a long way to go.

All storms require a source of energy to keep their water in the air, and the air moving. For tropical cyclones, the source is the air found just over the ocean near the equator. Because this water is warm, so is the air above it, which rises, carrying moisture upward. This leaves less air near the surface, creating areas of lower pressure. This mechanism—warm air rising, lower pressure near the surface—is what sustains a hurricane, and why hurricane season peaks at the end of summer. A hurricane can form only when the water temperature of the top 150 feet of the ocean is at least 80°F, and that is most likely to occur after months of long days heating the ocean.

Of course, hot air rises everywhere—there need to be more conditions in place than just a warm ocean for a hurricane to form. First, the area of higher temperature must be surrounded by cooler areas. When the hot air rises and lowers the pressure of a region, the air around it, at higher pressure, will flow into the low-pressure area. That “new” air becomes warm and moist, and it too rises, perpetuating a cycle.

As the water vapor rises into the higher levels of the atmosphere, it approaches cooler air. The differential between the warmer air and the cooler air causes the vapor to condense back into water droplets, forming clouds. The energy that was needed to evaporate the water gets release...

This process gets water into the air, but the storm’s rotation—the high winds characteristic of a hurricane—is dependent on the Coriolis force caused by the earth’s rotation. The Coriolis force is zero at the equator and increases toward the poles. Hurricanes can form only in the band that is far enough away from the equator (at least three hundred miles) to get spin going, but close enough to the equator that the w...

The last factor in the formation of a hurricane is the absence of what’s called vertical wind shear. That means the direction and speed of the overall wind pattern can’t change much as air rises up through the atmosphere. If the rising hot air were to hit winds blowing in different directions, it wouldn’t continue its straight ascent—it would get pulled sideways, disrupting the...

Considering the physical devastation, it’s a wonder that more lives weren’t lost. The three coastal counties had a combined population of four hundred thousand people. But the state of Mississippi began issuing evacuation orders on Saturday, August 27, and the region had been largely vacated by the time the worst of the hurricane struck. The total death toll across Mississippi was 238.

On Friday night, August 26, fifty-six hours before Katrina’s eventual second landfall, the NWS issued an ominous warning to residents of the Gulf Coast. MOST OF THE AREA WILL BE UNINHABITABLE FOR WEEKS…PERHAPS LONGER…HUMAN SUFFERING INCREDIBLE BY MODERN STANDARDS. Not all states responded as quickly as Mississippi, with its mandatory evacuations. The state of Louisiana and the city of New Orleans both waited until nineteen hours before landfall to mandate evacuation, leaving residents with precious little time to respond.

The emergency planning for hurricanes was close to useless. Hurricane Pam offered a remarkably accurate picture of what was to come, but the city planned for much less. Army Lieutenant General Russel Honoré, who arrived in New Orleans on Wednesday, August 31, to lead the military’s support operations, described the situation at the Superdome as “a classic example of officials thinking about the worst-case scenario but providing only enough resources for the best-case scenario.” Supplies were inadequate. There was no emergency operations center. The city didn’t know how the national incident command system worked. Where Mississippi began evacuations fifty-six hours before landfall, Governor Kathleen Blanco of Louisiana and Mayor Ray Nagin of New Orleans delayed evacuations. Problems with communicating these orders weren’t taken into account. Search-and-rescue teams weren’t supplied with boats. The list is endless.

The mobilization of federal resources to support recovery provided a great new vista for corruption. Billions of dollars poured into New Orleans, falling into cracks between the fighting city, state, and national governments. The public outcry against FEMA helped ensure that funds streamed in, but much of it got diverted. Mayor Nagin left office in 2010, but he was convicted in 2014 on twenty of twenty-one bribery and tax evasion charges. He has the dubious distinction of being the first New Orleans mayor to be convicted of corruption. The state of Louisiana suffered from corruption as well. A program administered by the state called A Road Home, intended to help people rebuild and return to New Orleans, received $1 billion in federal money. An investigation in 2013 found that 70 percent of this money, or $700 million, was unaccounted for.

The argument that formed the basis of De Bernardinis and Bertolaso’s reassurances—that small earthquakes reduce the risk of big earthquakes—is patently false. It is a bit of folk wisdom, one that I am asked about frequently, and that arises from nothing so much as wishful thinking. Big earthquakes release more energy than small ones. If we have a lot of small ones, the argument goes, shouldn’t that release the pent-up energy? While it makes intuitive sense, it contradicts the most consistent feature of earthquakes we’ve observed—one that Charlie Richter saw in the first set of earthquakes for which he calculated magnitudes, that we see in every aftershock sequence, and that occurs in any regional grouping of earthquakes around the world. The relative number of small to large earthquakes is constant. More small earthquakes means more big ones. Mathematicians call this a self-similar distribution.

With the Richter scale, this means that if there is one magnitude 3, we can expect approximately ten magnitude 2s. If there is one magnitude 6, there will be approximately ten magnitude 5s, one hundred magnitude 4s, and one thousand magnitude 3s. We may see small variations, of course. But this distribution is a truism in seismology. No seismologist would ever suggest that having many small earthquakes would make a bigger earthquake less likely.

Nuclear power plants harness the huge amount of heat generated by the splitting of the nuclei of large atoms, like those that make up uranium. This heat is used to create steam, which in turn is used to drive electric turbines and create the energy many of us consume in our daily lives. But the heat created in these nuclear reactions needs to be managed, to be drawn away from the nuclear fuel, or else we risk it melting, which will cause the vessel that contains the fuel to explode. So nuclear fuel is kept in circulating water to dissipate its heat. As a consequence, nuclear power plants are always built near major water sources, often the ocean, to facilitate cooling. Additionally, they have redundant backup power systems to make sure the heat management systems don’t fail.

The first surge of the tsunami hit Fukushima almost an hour after the earthquake, at 3:41 p.m., with a second, even larger surge eight minutes later. The seawater pumps, whose engines had been sealed a decade prior, could withstand the waves, even at the massive scale they were experiencing. It was in the backup generators that the vulnerability lay. They were at too low a level and were completely inundated by the forty-foot-plus waves. As a consequence, the cooling systems failed for three of the six reactors on the site. Without effective cooling, the reactors overheated. Pressure built and nuclear fuel melted. It was only a matter of time before reactors began to explode.

Over the next month, as the nuclear crisis unfolded, they discovered that the situation was much worse than they’d been told, especially for residents of Fukushima. The reactors and spent fuels continued to overheat, requiring them to be bathed in untreated seawater. Seawater is corrosive, and leaks developed. Fires broke out, carrying more radiation into the environment. Storms and wind currents carried the radiation to the northwest—toward Fukushima. Radiation levels in the vicinity grew. After two weeks, even the tap water in Tokyo, over 150 miles south, showed twice the safe level for infants. By the end of March, radiation levels in the seawater immediately adjacent to the plant had levels of radiation that were 4,385 times what was considered safe. It was only with this absolute proof of the severity, a full month after the incident began, that the Japanese government revised the rating of the incident to a 7—on par with Chernobyl.

Remember that disasters are more than the moment at which they happen. To effectively manage disasters, we must, as communities and individuals, focus on three different times: we must adequately build and retrofit our structures before the event, to minimize damage; we must respond effectively during the event, to save lives; and we must come together as a community after the event, to recover. Recognize that all three periods are important. Expand your definition of preparedness beyond simply preparing to respond.