Buy the Book: Natural disasters shape the planet in many ways. The Big Ones details some of the biggest natural disasters in human history, how people were impacted, and how they responded to the randomness of each event.
The Notes
- California has not gone more than 12 hours without an earthquake since the 1990s (when the seismic network was built in the state).
- Plate tectonics push L.A. toward San Fran at a rate of 2 inches per year.
- The worst events are never caused by one factor alone. The biggest risk with natural disasters is second-order effects — widespread damage, from fires, flooding, etc., triggered by the disaster.
- We can generally predict where a natural disaster occurs but not when. Rivers flood, big faults create earthquakes, and volcanoes erupt. It’s the timing and size of the disaster that’s random and unpredictable. And people don’t like random. The best we can do is have a system in place to prepare, respond, and recover from it.
- People that live in high-risk areas not only have to worry about the risk but how their biases — complacency, overconfidence, and the illusion of control — affect their view of the risk.
- “Psychologists describe a “normalization bias,” the human inability to see beyond ourselves, so that what we experience now or in our recent memory becomes our definition of what is possible. We think the common smaller events are all that we have to face, and that, because the biggest one isn’t in anyone’s memory, it isn’t real.”
- “One of the human species’ greatest strengths is its ability to theorize. Evolutionary pressure rewarded brains that saw patterns, even in randomness… At a primal level, we abhor randomness because it leaves us vulnerable.”
- “Randomness means you cannot use what came before to predict what will be next.”
- “Natural hazards are part and parcel of the systems that make life possible on our planet. The distribution of heat through the atmosphere that coalesces into storms is the same movement necessary to bring water out of the oceans, to rain upon land. A planet without earthquakes would be one without mountains and valleys with which to trap clouds, or faults to trap groundwater and bring it to the surface in springs. Natural disasters, as we’ve seen, are a consequence of the inevitable fluctuations in the natural environment necessary to support life.”
- Population centers in high-risk areas for natural disasters rarely focus on prevention or limiting disaster until after the fact. Because spending a ton of money on an unknown event, especially once in a 100-year type event, is easier to put off. Of course, the cost of a disaster is magnitudes larger.
- “For most of us, the future remains an abstract concept. We show a remarkable ability to forget past disasters, or to minimize their imagined impact.”
- “In the face of loss and failure — no less a failure of this magnitude — we often turn to blame. We have a deep-seated aversion to having our missteps exposed, and we look for ways to avoid it. Blame provides an emotional outlet. It can also, in the wrong hands, be used as an explicit ruse to divert attention away from oneself.”
- Prior to the advancement of science, divine retribution was the main reason given to why natural disasters occur.
- “One of the most important tenets of research science is the acknowledgment that the easiest person to fool is yourself. All human beings, including scientists, are inclined to confirmation biases — we are less critical of information that supports our preexisting beliefs and more critical of data that confounds them.”
- “Part of what inhibits us from taking action to prevent human catastrophe is our uncertainty about when an event will happen. A risk that has a lower probability of occurring in any given year is inevitably displaced by more immediate concerns.”
- “Successful prediction in any discipline requires evidence of an event preceding the occurrence you’re trying to predict.”
- Most safety measures put in place by governments are in response to a recent disaster rather than in the prevention of a future one. So the response is tied to recency bias (always fighting the last war) and rarely prepares for a worst-case scenario. “Preparing for the Big One is categorically different from preparing for the sort of big ones.”
- Volcanoes
- Volcano eruptions are measured by the Volcanic Explosivity Index (VEI) or how much material is thrown, to what height, and for how long. It’s on a scale from 0 – 8. Vesuvius was 5. Laki was a 6.
- Have the highest potential for damage and disruption.
- Volcanoes appear in three tectonic settings: mid-ocean ridges, subduction zones, and hot spots.
- Stratovolcanoes
- Are found in subduction zones, where one tectonic plate is pushed under another. It happens at a rate of one to a few inches per year. The plate being pushed down ultimately melts before being recycled.
- Tend to have explosive eruptions — due to water and other gases in the lava that expands rapidly when heated.
- Eruptions can reach tens of thousands of feet into the atmosphere.
- Pyroclastic flows: hot gas and ash, heavier than air, that flows rapidly down a mountain, at speeds of 50 mph or more (300 mph has been recorded) at a temperature of 500°F. Death is instant.
- Earthquakes
- Earthquakes are measured by magnitude. Magnitude is determined by the distance of the slip, the length of the fault, and the depth the friction is held.
- “The smallest earthquakes are the most common. Magnitude 2s are so small they are felt only if someone is very nearby their epicenter, and one happens somewhere in the world every minute. Magnitude 5s are big enough to throw objects off shelves and damage some buildings; most days a few of these strike somewhere. The magnitude 7s, which can destroy a city, occur more than once a month on average, but luckily for humanity, most take place underwater, and even those on land are often far from people.”
- A rupture is the extent of slip that occurs on a fault, which causes an earthquake. The slip is a reduction in friction that allows a fault to move at lower stress. The size or magnitude of an earthquake is determined by the distance the rupture travels. “If it moves a yard and stops, it is a magnitude 1.5 earthquake, too small to be felt. If it goes for a mile down the fault and stops, it’s a magnitude 5, causing a little damage nearby. If it goes on for a hundred miles, it is now a magnitude 7.5, causing widespread disruption.”
- A slip is best described as the distance between two objects after an earthquake that were once standing next to each other. A slip of 100 feet means the earthquake moved the two objects 100 feet apart.
- “Wherever there are earthquakes, the ratio of large to small earthquakes is stable. That means that places where smaller earthquakes happen are those more likely to see big ones… But in the same way that a high concentration of small earthquakes doesn’t necessarily mean a big one is coming soon, the absence of small earthquakes doesn’t mean an area is immune to one. How big is limited only by the length of the fault available to break.”
- Earthquakes create two types of waves. P-waves compress the ground. S-waves twist the ground. S-waves travel slower than P-waves but are bigger. The time between the two waves is used to estimate where an earthquake originated because it grows at a rate of one second every five miles the waves traveled.
- Loose sediment passes seismic waves more slowly than rock and packed soil, which amplifies the waves 10x or more.
- Bigger earthquakes produce lower-frequency energy that does more damage to bigger buildings compares to smaller ones.
- Aftershocks are not random. “When one earthquake happens, other earthquakes become more likely. The movement on a fault stresses everything around it, creating new irregularities, concentrations of stress. Subsequent earthquakes will result to relieve those new stresses. Because those earthquakes are expected and are a direct result of the preceding quake, we call them aftershocks.”
- Aftershocks follow a decay pattern that drops off in time. The drop-off is quick but has a very long tail.
- Vertical faults show a concentration of shaking on the surface as a line. More horizontal faults show a shaking on the surface that is much wider.
- The WWSSN (Worldwide Standardized Seismograph Network) is 120 seismic stations around the world to monitor underground nuclear explosions set forth in the 1963 nuclear test ban treaty. It also happened to measure every 5.5 magnitude earthquake around the world.
- Damage to underground tunnels is rare because of their stable shape and shaking underground is half that of the surface.
- Most cultures that experience earthquakes fabricate patterns, where none exist, in an attempt to predict them. Whatever pattern they recognize, like the weather or animals, gets attached to a quake. Pliny the Elder was one of the first to attribute weather — winds — as the cause of earthquakes. Of course, the patterns are random. Animals can’t foretell earthquakes. Neither does the weather.
- “The nature of earthquakes is such that you can appear to be successful in finding patterns for quite a long time before you have to face the fundamental failure of your prediction. Earthquakes happen all the time, after all. It is remarkably easy to be right just by random chance… A method needs to show predictive validity over multiple events and be demonstrably better than random chance. We have fallen victim, over the decades, to too many false alarms to demand less. Otherwise, our confirmation bias will fool us into thinking we’ve discovered a pattern.”
- “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.”
- Tsunamis
- Tsunamis are created by the biggest subduction zone earthquakes.
- Caused when the seafloor changes suddenly, pushing the water, creating a wave. The deeper the sea, the more water in the wave, and as the wave approaches the shore, the higher the wave.
- “A tsunami is a wave with multiple peaks and troughs. Instead of thinking of it as a very big ocean wave, you need to think of it more like the ripples that encircle a rock that you drop into a pool of water. A series of up-and-down movements travel out from a disturbance of the ocean floor. How many peaks and troughs, their relative sizes, and how far apart they are all depend on the shape of the seafloor, not to mention the shape of the coastline where the wave hits. If a trough arrives first, then the first sign of an incoming tsunami is not rising but receding seawater.”
- Most of the damage is done by the currents, not the flooding. A massive wall of water can carry away anything not anchored into the ground.
- The strongest waves are produced directly perpendicular to a fault.
- Floods
- Floods are classified by the probability of occurrence. A 100-year flood has a 1 in 100 chance of occurring in a given year.
- “To most of us, flooding doesn’t feel imminent. Without a personal association — firsthand experience, or else the recollections of a parent or grandparent, say — our connection to disaster can become so tenuous as to lose its emotional grip altogether. And when it comes to our evaluation of risk, emotion is often more powerful than reason.”
- “Flooding is always seen as more benign than other hazards, in spite of the huge death and economic toll it takes, because of the familiarity of its sources… Rain is so familiar as to feel benign… Its impact feels manageable. And most of the time, we manage it quite well. The other hazards — earthquakes, volcanoes, landslides — emerge from out of nowhere. They are erratic, invisible, a sudden disruption to the earth.”
- Floods are like earthquakes in that small floods occur much more often than big floods, and the largest floods are rare.
- “Hydrologists measure flow rate every day. They plot out daily rates for many years. They can say that a stream has a high probability of exceeding the low value in any given year, a moderate probability of exceeding the high value, and a very low probability of exceeding the very high value. The flow rate that has only a 1 percent chance of being reached at any time in one year is called the hundred-year flood. You can push out the distribution curve, assuming that this relationship of large to small will continue, and estimate the thousand-year flood — the flood that has only a 1-in-1,000 chance of happening this year. That’s a low probability, of course; but with thousands of rivers, each receiving different storms, we see a “thousand-year” flood somewhere in the world most years.”
- Historical flood data in the U.S. is only about 100 years old. We have no idea how bad floods were before then. The lack of data makes it hard to predict and prepare for future floods. Global warming likely makes existing data less relevant.
- Most governments aren’t even willing to accept that a 1,000-year flood is possible, much less spend the money to plan for one.
- Two things about rivers: “A river is whatever land is needed to accommodate its flow… 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.”
- “Floods are unique among hazards in that, in coping with them, we must balance the need for containment with our other essential uses for water. Floodwater must be disposed of, but it must also be preserved for dry times (only more so in the arid West), while also retaining access to rivers for the transport of goods. In flooding, our most ubiquitous hazard, our need for protection can be at cross-purposes with our other economic necessities.”
- Spring is the deadliest time for flooding because of the combination of melting snow and rain.
- Hurricanes
- Measured by wind speed. Tropical storms exceed 39 mph. Category 1 begins at 74 mph. Category 5 begins at 157 mph.
- Hurricanes are rapidly rotating thunderstorms with strong winds.
- Can only form when the top 150 feet of the ocean is at least 80°F, which typically occur at the end of the summer near the equator.
- Factors to form a hurricane:
- “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 released in the process. The air is now even hotter, causing it to rise even more.”
- Coriolis Force: essentially gets the spin going. Coriolis force is caused by the earth’s rotation, is zero at the equator, and increases as you move to the poles. Hurricanes can only form in a small band that is far enough from the equator to get a force greater than zero but close enough to where the water temperature is at least 80°F. Once the storm starts spinning it pulls more air into the region.
- An absence of vertical wind shear: the direction and speed of the wind need to be consistent and unchanged. Any crosswinds or disruption can interrupt the spin.
- “Because hurricanes are driven by warm ocean temperatures, most scientists expect to see an increase in both their number and strength as global warming progresses.”
- Hurricane Patricia in 2015 was the strongest ever recorded. Hurricane Harvey in 2017 dumped the most rain ever. Hurricane Irma in 2017 had the longest duration of extreme winds ever recorded.
- Damage is done by strong winds, that destroy structures and push water (storm surge), and heavy rain that leads to flooding. A slow-moving Category 1 hurricane can do more damage with flooding than a fast-moving Category 4.
- Data collection and modeling have improved the accuracy of predicting the path and strength of hurricanes. The National Weather Service (NWS) predicted the path of Katrina within 15 miles and the wind speed within 10 mph.
- Pompeii, AD 79
- “Plate tectonics might guarantee that the next event will happen, but which generation will experience the extreme event is determined by chance. And for most human beings, as for the inhabitants of Pompeii in AD 79: if it hasn’t happened to me, it simply hasn’t happened.”
- Why build a city near a volcano? Volcanic soil is fertile, full of nutrients, and holds water well.
- Vesuvius had gone 600 years without an eruption — it last erupted in the sixth century BC — making it seem safe. The first century BC saw three towns built around the volcano — Pompeii, Herculaneum, and Misenum.
- Vesuvius experienced an explosive eruption on August 24 AD 79.
- Pompeii was completely covered in ash in a matter of two weeks.
- 90% of Pompeii’s residence escaped alive.
- Vesuvius is a stratovolcano.
- Lisbon, Portugal 1755
- The largest earthquake in the Azores-Gibraltar seismic zone in human history.
- The estimated magnitude was 8.5 to 9.0.
- Happened on All Saints’ Day, 1755, and began at 9:40 a.m.
- The timing of the quake, on a holy day, led most people to believe it was far from random chance — divine retribution.
- 85% of the buildings were destroyed by the earthquake or fires. The damage was worse near the river.
- Those that survived the earthquake, and the aftershock, were met with a tsunami that traveled up the river. Many congregated near the river believing it was safer.
- Sebastião José de Carvalho e Melo headed the recovery and reconstruction, one of the first government responses to a natural disaster. It was highly effective.
- De Carvalho created building codes for earthquakes. He also one of the first to do a scientific survey of the quake.
- Conservative estimates of 40,000 to 50,000 people died.
- Laki, Iceland 1783
- Generally believed to be the deadliest natural disaster in human history. Millions died as a result.
- The entire country of Iceland is an active volcano.
- The eruption on June 8, 1783, lastest eight months. It dropped a 55-foot thick mass of lava over 600 square miles (roughly the size of Rhode Island), covering 1/6th of Iceland.
- Most of the lava came in the first 45 days from 10 different fissures.
- Each fissure followed a pattern: series of earthquakes over a few days to weeks, a fissure would open, lava would rise through water in the ground, creating an explosive eruption, until the water evaporated causing surface flow.
- Laki produces three times the lava in that eight-month period than Mount Kilauea has in 30 years of continuous eruption.
- The biggest risk after the lava stopped flowing was poisonous gas and famine. The lava wiped out the most fertile region of Iceland and the poisonous gas — hydrogen fluoride and sulfur dioxide — killed 60% of the livestock. Eight million tons of hydrogen fluoride, which deforms bones and destroys teeth, settled over Iceland.
- The eruptions were so powerful they pushed sulfur dioxide into the upper atmosphere carrying it to Europe and beyond. This is what made the event so deadly.
- Ash and sulfur dioxide spread to France by June 14, and the rest of Europe by the month’s end. And it lingered through the summer. Newspapers reported unexplained illnesses and deaths. The following winter was abnormally cold. Rivers froze over and flooded in the spring, shutting down transportation for months. The eruption set off a cascade of famine around the globe.
- California, U.S. 1861
- A flood in 1861 was the most devasting event in California history.
- 300 miles of California’s Central Valley was covered in 30 feet of water.
- A measure of extreme rainfall is whether a storm produces over 16 inches of rain over a three-day period. Few places outside hurricane zones experience that amount. California is the exception. The Sierra Nevada mountains have seen that amount of extreme rain seven times.
- California was hit by rain from December 1861 through January 1862, then it got worse. It rained for 45 days.
- “Since November 6, when the first shower came, to January 18, it is thirty-two and three-quarters inches and it is still raining!.. This year at Sonora, in Tuolumne County, between November 11, 1861, and January 14, 1862, seventy-two inches (six feet) of water has fallen, and in numbers of places over five feet! And that in a period of two months.” — William Brewer (scientist), his personal account
- The rain flowed down from the Sierras, rivers flooded, filled the valley, and took most of the next year to drain. Farmland flooded, crops ruined, and herds drowned. Hundreds of small towns were partially or totally lost to the flooding. Most of Sacramento sat in eight feet of water for months. Outside communication was cut off in many places for months or more.
- Landslides were common, bringing boulders and other debris, which transformed the land.
- “The “Lake” was at that point sixty miles wide, from the mountains on one side to the hills on the other… Nearly every house and farm over this immense region is gone. There was such a body of water — 250 to 300 miles long and 20 to 60 miles wide, the water ice cold and muddy — that the winds made high waves which beat the farm homes in pieces.” — William Brewer
- The economic damage was huge. Businesses were wiped out. It transformed the economy. Property tax records show 1/3 of taxable land was destroyed in the flood. The state went bankrupt.
- Tokyo-Yokohama, Japan 1923
- On September 1, 1923, at 11:58 a.m., a magnitude 7.9 earthquake that destroyed Tokyo and Yokohama was one the deadliest in Japan.
- Four colliding tectonic plates formed Japan — Eurasian plate, Pacific Ocean plate, Philippine Sea plate, and North American plate. The four plates push into each other creating a subduction zone with one of the highest rates of earthquakes.
- Yokohama sat atop the fault. The initial quake lasted for 40 seconds — Tokyo was even longer. Fires started within minutes. Aftershocks above magnitude 7 hit within 10 minutes, making it impossible to control the fires.
- 80% of the building in Yokohama and 60% in Tokyo were destroyed. Over 140,000 people died.
- Mississippi, U.S. 1927
- The Mississippi River is the 3rd largest watershed, gathering water from 32 states (40% of the U.S.) and 2 Canadian provinces.
- The last 450 miles of the Mississippi riverbed is below sea level. Because the riverbed is below sea level, the current isn’t uniform. Water near the top flows faster than the water near the bottom. Bends in the river produce a similar effect, where water at the outside of the curve moves faster than the inside. Faster moving water can more easily scrape away and move dirt at the edge of the river, which makes it harder to build levees.
- “The Mississippi River will always have its own way; no engineering skill can persuade it to do otherwise.” — Mark Twain
- Rains began in August 1926 in the upper midwest states and continued into October. River gauges showed record-high levels from flooding on the Ohio, Missouri, and Mississippi rivers. Then the lower Mississippi watershed was hit by five storms from January to February. By April, flooding along the tributaries put a million acres underwater.
- The combination created the worst-case scenario for a catastrophic flood. So much water entered the lower Mississippi River by spring that the levees were at risk of failing.
- The main levees, at the time, were two to three stories high and set back from the river by a half-mile or more.
- A storm on April 15 sealed it. 15 inches of rain fell over 18 hours. A 12,000 foot stretch of levee broke the next day, flooding 175,000 acres immediately. Within days other portions of the levee broke. Mounds Landing saw a million acres flooded in 10 feet of water.
- President Coolidge, at the time, refused to act as it was a “local affair.” The Red Cross filled the void thanks to donations, though refugee camps were segregated, so food, provisions, and medical care were not distributed equally.
- It was the worst flooding of the Mississippi…on record.
- Tangshan, China 1976
- A magnitude 7.8 earthquake hit Tangshan in the early morning of July 27, 1976. Most people were asleep at the time.
- The exact amount of devastation is unknown due to the misinformation out of China. Early estimates were 750,000 people died. Those numbers have since been revised downward multiple times by the government.
- The Indan Ocean 2004
- A magnitude 9.1 earthquake created a tsunami that hit Sumatra, Indonesia on December 26, 2004. It was the third-largest quake ever recorded. The fault was over 900 miles, the longest rupture ever.
- Because the quake happened in the Indian Ocean, few people felt it. But it displaced the third-largest volume of water and the biggest wave ever recorded.
- “The energy released in the event was a thousand times larger than that of the largest hydrogen bomb ever detonated. Its human impact was no less momentous.”
- Aceh Province was the first to get hit with waves 50 to 100 feet high. Over 200,000 people died or missing.
- 90 minutes after the quake, the tsunami had crossed the Bay of Bengal and hit Sri Lanka. Wave heights ranged from 13 to 40 feet, more than 40,000 died.
- Two hours after the quake, the tsunami reached Thailand to the east. Wave heights reached upwards of 64 feet.
- It would eventually reach the coast of Africa and spill into the Pacific and Atlantic Oceans.
- “In total, it struck thirteen countries, causing damage to infrastructure and buildings in five more. Forty-seven others lost citizens who were traveling abroad, many of them vacationers in Thailand. In this respect, it was not only a massive physical event with a devastating human toll; the Sumatran tsunami was the world’s first truly global disaster.”
- New Orleans, U.S. 2005
- Hurricane Katrina was the deadliest natural disaster in the U.S. since the 1906 San Francisco earthquake.
- New Orleans is the only major city that sits within an active delta (it’s the only one because it’s a bad place to build a city). It also sits below sea level, as much as 20 feet below.
- Katrina made landfall on August 29. The eye of the storm was east of New Orleans, in Mississippi. Storm surge near the eye reached 28 feet high. Everything along the coast was destroyed. The total financial losses in Mississippi exceeded $125 billion.
- Mississippi began evacuations two days before landfall. Total deaths in the state were 238. Louisiana and New Orleans failed to issue evacuation orders until 19 hours before landfall. An earlier evacuation would have saved countless lives.
- The first reported levee breach was almost immediately after landfall, more occurred over the next 24 hours. Pumping stations stopped working, which only made it worse. Two days after landfall, 80% of New Orleans was underwater by as much as 20 feet. The flooding knocked out sewage, drainage, power, supply chain, and communications. The total number of deaths in New Orleans is unknown — they stopped counting at 1,464.
- It was known in 2005 that the levee’s built to protect New Orleans were old and insufficient. “The Louisiana Water Resources Research Institute at Louisiana State University had completed a scientific study showing how the process of delta formation had turned New Orleans into a deep bowl waiting to be filled by a storm surge. The confinement and destruction of wetlands along the coast compounded the problem.”
- The response was an abject failure of local government: delayed evacuations, inadequate supplies, no emergency operation center, lack of cooperation between federal/state/local government, and corruption.
- “Failure at such a massive scale requires many smaller failures from many players.”
- Tohoku, Japan 2011
- A magnitude 9 earthquake hit just offshore, east of Fukushima. It was the fourth-largest ever recorded, with a 250-mile long fault with a slip of 240 feet (twice the largest ever).
- “It was an earthquake most seismologists would have said couldn’t happen — until it did.”
- Initial damage from the earthquake was minimal thanks to building codes. Only 150 people died from the quake.
- The earthquake created a tsunami, that did most of the damage. Levees were in place for tsunamis but since the earthquake exceeded all predictions, it wasn’t enough. The tsunami reached over 45 feet high. 18,000 died from the tsunami.
- “What turned this event into a national catastrophe was not the earthquake alone, or even the pairing of earthquake and tsunami, but these two natural events in conjunction with one other significant man-made factor.”
- The Fukushima nuclear plant wasn’t built to withstand such a huge tsunami. That’s despite several upgrades to the design based on a higher possibility of larger tsunamis. The 40-foot waves knocked out the emergency generators, caused the cooling systems to fail, which led to a nuclear meltdown. It was the worst nuclear incident since, and on the same scale as, Chernobyl.
