The world's most dangerous countryBy Neil Spector and Nicholas K. Coch | July 1, 2014
Neil Spector, president of Verisk Insurance Solutions – Underwriting, sat down with Nick Coch, professor in the School of Earth and Environmental Sciences at Queens College and an expert on coastal geology, geologic hazards, and hurricane damage patterns. Nick has presented lectures to emergency management and insurance groups in the United States, Canada, and the Caribbean and is a Sigma Xi Distinguished Lecturer. We’re privileged that he took time from his busy schedule to talk to us here in our Jersey City, New Jersey, headquarters. Nick shared his views about “the world’s most dangerous country.”
Neil Spector: The United States is prone to a multitude of different natural disasters. Can you talk about some of the hazards you study?
Nick Coch: First of all, people should realize the United States is basically the most dangerous country in the world because of its geologic and geographic position. No other country has mountains on both oceanic shores. With arctic air to the north and tropical air to the south, the central United States is prone to severe weather. In addition, the United States contains every known type of volcano, including a supervolcano in Yellowstone, as well as every known type of earthquake.
Spector: What is it about the geology of the United States that makes it the most dangerous country?
Coch: From a geological perspective, the eastern portion of the United States is relatively stable because the underlying rocks are much older and settled. But in the western part of the country, rock masses came together only in the recent geologic past and are subject to reorientation from stresses caused by the moving plates of the earth’s crust.
On Hurricane Risk
Spector: Before the interview, you mentioned that hurricanes in the North differ from those in the South. Can you share the difference with us?
Coch: In a paper to be published at the end of this year, I established three basins of hurricanes: hurricanes in the Gulf of Mexico, those in the South Atlantic, and those in the North Atlantic. Any hurricane that enters the Gulf has the potential to intensify two to three categories in one day because the Loop Current — the ocean’s warmest water — is situated there. If a hurricane track crosses part or all of the Loop Current, it’s going to intensify and develop into a bigger storm, possibly as strong as Katrina or Rita.
South Atlantic hurricanes, those that hit from Florida to the Carolinas, are the ones that obey the rules, the textbook cases. But the North Atlantic hurricane, which extends from Virginia northward, is a totally different species. That’s because it’s moved not by the trade winds — easterly winds from the south — but by winds from the west. Once a hurricane moving northward enters the westerly winds, it accelerates because the westerly winds are much stronger at the upper levels. Under the influence of the westerly winds, a hurricane moves faster, increasing the effective winds on the right side as well as expanding its wind field. That means a hurricane moving up the Atlantic coast keeps its weak side against the coast. However, when it reaches the Northeast, the powerful right side of the storm can move far inland.
In 1938, the Great New England Hurricane hit the south shore of Long Island on September 21 at 2:30 p.m. At 5:30, the storm was killing people in Providence, Rhode Island, as it drove Narragansett Bay into the downtown area. At 1:30 in the morning, the hurricane was knocking trees over in Montreal, several hundred kilometers from the ocean. The Canadian Hurricane Centre lists that storm as one of the three official Canadian hurricanes.
Spector: Many people view large hurricanes as long-horizon events — meaning there’s a lot of time between such storms. We recently experienced Superstorm Sandy here in the Northeast. Do you predict that a long period of time will elapse before the next event?
Coch: Superstorm Sandy was an anomaly. It was an unfortunate convergence of five different factors that most likely will never come together again. Sandy was different in that it curved west because of the positioning of the jet stream induced by the warming trend we’ve been having. So I believe that Sandy was not the anticipated “big one.” The big one is yet to come, roughly averaging 100 years. The last such hurricane was 1938. Keep in mind that the next one is going to hit the country’s most urbanized and developed area responsible for banking, entertainment, and so many things. The consequences could be astronomic, and the insurance industry should begin preparing now.
Spector: What are some of your recommendations to both the industry and public officials in preparation for such an event?
Coch: It’s imperative to have a better understanding of the science of hurricanes and realize there are a number of factors beside the intensity (Saffir-Simpson category) of the storm that influence damage. A Category 2 storm hitting at high tide can do considerable damage, whereas a more intense Category 3 storm at low tide may do relatively little damage. A suburban area where there are no structures to interfere with the wind will experience a storm differently than an urban area.
A hurricane creates damage in three separate ways: wind, saltwater surge, and freshwater flooding. As the hurricane moves on land, convection bands drop tremendous amounts of rain while the storm itself pushes saltwater inland, creating higher-than-normal water levels. I surmise that when a hurricane hits an urban area, the first effect isn’t saltwater surge. What actually occurs first — even before the hurricane reaches the shore — is freshwater flash flooding due to rain that has nowhere to go because of extensive surface paving.
On Other Catastrophes
Spector: We’ve talked a lot about hurricanes, and I know that’s a popular topic in the insurance industry. But what other types of catastrophes do you think insurance companies need to be concerned about?
Coch: There’s a growing threat from tornadoes. As temperature differences between arctic air and gulf air increase, the contrast as they converge in the central part of the continent makes conditions more violent. I think the drying out of the forests of the West is going to cause a great exposure in terms of increased wildfires. Such vegetation contains resins and oils that enable it to survive without much water, but those conditions also make forests highly flammable. The resulting fires can spread into urban settings such as San Diego and Los Angeles.
I don’t have much to say about volcanoes and earthquakes because we just can’t predict when they’re going to occur. But certainly, hurricanes are going to increase the coastal exposure of the insurance industry. As the ocean gets warmer, hurricanes can move farther north. So, maybe the hundred-year frequency of the “big one” will change in the coming decades to 50 or 75 years.
Spector: There have been a number of global incidences involving tsunamis in recent years. We don’t usually think of the United States as a significant tsunami risk. Can you talk about what risks the threat poses to the United States and other countries?
Coch: We’ve traditionally thought of tsunamis as a hazard in the Pacific. But we now know the potential for tsunamis exists as well in the Atlantic, stemming from the Cumbre Vieja volcanoes in the Canary Islands, according to British geologists. Although we have a tsunami threat in the inland Atlantic, it’s not something I would worry about. The Pacific, however, is a much more active region with much greater potential for such an event. Plate tectonics — the large-scale movement of the earth’s outermost shell — causes earthquakes that in turn generate tsunamis. The Hawaiian Islands, Alaska, and Chile all have the potential for aggressive tsunami activity that could affect low-lying areas of Los Angeles and other urban centers within tsunami zones.
Spector: What is a typical warning time frame for a tsunami?
Coch: About ten hours. The U.S. government has installed sensors in the Pacific Ocean that can detect the movement of a tsunami wave. As soon as an earthquake occurs anywhere, we receive signals on U.S. government seismographs that indicate where the tsunami originated. So, we have a good system. The problem is in the Indian Ocean, where no monitors are located because of monetary constraints. That led to the tremendous tragedy of the Indonesian earthquake. The tsunami that followed was actually measurable and recorded in New York harbor.
Spector: Can you talk a little about the significance of the rise in water levels?
Coch: Regardless of your views on climate change, the evidence is clear that sea levels are rising. For example, there are villages in the South Pacific that are now completely under water. The simplest explanation for the sea level rise is the melting of the ice sheet due to global warming. In addition to snowmelt, the ocean is getting warmer. And as water heats up, it expands. So the combination of these two things — the melting of glaciers and the warming of the ocean — leads to acceleration of sea level rise, which will make living in coastal areas extremely hazardous.
Spector: In your opinion, what are some of the most severe natural disaster scenarios?
Coch: I’m most concerned about a major hurricane striking an urban region. Surprisingly, the only hurricanes that have hit the heart of a major urban area occurred in New York City in the 1800s. Most people think that Hurricane Andrew hit Miami, but the city escaped relatively unscathed. We’ve been incredibly lucky that hurricanes missed Houston, as well as Tampa, Florida, and Norfolk, Virginia. Hurricanes hit New York City directly in 1821 and 1893, but when you extrapolate the destruction of those low-category hurricanes with present population and development, what would happen? It’s only a matter of time before our luck runs out.
Spector: Tell us something that most people probably don’t think about often. What is the threat of Yellowstone?
Coch: The Yellowstone Caldera is America’s supervolcano. Geologically, Yellowstone extends deep into the earth’s mantle, which means a tremendous amount of molten rock can come directly to the surface. That’s the source of all that bubbling water and steam. And the Yellowstone supervolcano is very predictable. It erupts about every 640,000 years — and we’ve now exceeded that limit.
Spector: What are the implications of Yellowstone erupting?
Coch: An eruption of Yellowstone would result in the incapacitation of a third of the United States directly by ash fall and gas. There are also tremendous implications for global climate change and the geological equivalent of a nuclear winter.
On Climate Change
Spector: Climate change is a hot topic. It’s political, but it’s also potentially behind a lot of the disasters or can influence the disasters you’ve been talking about. Can you share your views on the subject?
Coch: There’s no question in my mind that the climate is changing. Years ago when I first heard about climate change, I asked an expert if we were going to have warmer summers. He said yes but noted that we’d experience “crazy” weather first. I don’t think there’s a single person who could deny that tornadoes, flooding, and rainfall rates have increased. Why? Because as the ocean warms, more moisture evaporates. That evaporation has to go somewhere, and it causes a lot of trouble in the process. Paradoxically, we’re going to see an increase in both dryness and wetness. We’re going to see patterns that we can’t predict. The models show different scenarios. We don’t know what will happen, but we do know that we’ll experience these differences.
Spector: Here in the Northeast and a large part of the country, we had a particularly harsh winter. People are skeptical that the reason is global warming. Can you tell us what caused the extreme cold?
Coch: First of all, it’s always going to be cold in winter. But what’s different is that the cold has become more intense and long-lasting. Believe it or not, that’s attributed to global warming. Warm, moist air is moving to the poles, displacing cold air over the polar vortex. That cold air is being pushed south. That’s a plausible explanation, even though it’s counterintuitive that heat can cause the cold.
On Urban Planning
Spector: We’ve talked about the urban exposure to hurricane, and you mentioned cities like New York, Miami, Houston, Tampa, and Norfolk. Can you name others?
Coch: Boston and Philadelphia — those are the major cities, but you can also add Charleston and Savannah. I’m worried about the consequences in cities with the largest populations and structures.
Spector: What’s your experience with planning for hurricanes in those cities?
Coch: It varies from city to city. In New York, when I started studying hurricanes at the end of the ’80s, we had a very primitive response to hurricanes. The police department handled those events, and in New York, they already had enough to do. Now, we have professional management. I’m very proud that we have an evacuation plan — and it’s a fairly good one for a big city. Mayor Bloomberg put parts of the plan into effect during Hurricane Irene, and it proved successful. We’ve come a long way in New York City — which is what I’m most familiar with — and I think that the current mayor is also inclined to administer the plan if necessary. Before we surround the city with huge sea walls, we have to address more obvious, practical concerns, such as protecting the subways and limiting the choke points on all arterial highway systems.
On Flood Zones and Coastlines
Spector: FEMA typically assigns flood zones based on natural disaster flood risks, yet some of the areas flooded after natural disasters haven’t been flood zones. Floods resulted from infra- structure failure or other unintended consequences of a disaster. Can you talk a little about that?
Coch: Perhaps people who reside in flood zones don’t understand what causes flooding. Take a look at what happened during Sandy. The news media reported surge levels of 9 feet. People living at 12 feet thought they were safe, but some drowned. Why? Because the media should have reported water levels, not just surge levels. First, you have the normal water level, then you add to that the tide, then you add to that the 9-foot surge, then you add the waves, which could be 30 feet high and driven by wind. Residents need to know the actual water surface, not the surge level.
Spector: What is your recommendation for areas that have built-up coastlines? They already have homes exposed to those risks. What should they do going forward?
Coch: The ideal approach would be for the government to buy out the residents at risk and establish zoning practices prohibiting construction in front of the dunes. Then build up the dunes with windblown sand, not bulldozed sand — because when you pile sand, it’s not as strongly packed as when the wind puts it in place. Bulldozed sand will be gone in a few minutes during a storm, whereas a natural dune is secured by grasses, such as Ammophila. Most coastal geologists agree that the only real plan — although it won’t be popular — is to institute buyouts. Don’t restore the houses on the sand; compensate the people and take that land. It’s going to be under water in a few years no matter what you do.
On What the Future Holds
Spector: I’ve asked you a lot of questions today and appreciate your comments. Is there anything else you’d like to share related to the work you’ve done or knowledge you’ve gained?
Coch: My principal concern is that no one can predict what’s going to happen in this new era of climate change. Will the trends be steady or accelerated? It’s essential that we try to limit global warming without pointing fingers, whatever it takes to cut back. Let me tell you a frightening scenario. All the continental shelves contain frozen methane, which is the gas we use in cooking. It’s formed from the anaerobic breakdown of organic material millions of years ago. In the cold ocean, it’s frozen like snowballs. Methane is at least 20 times more potent in global warming than carbon dioxide. What would happen if the oceans warmed sufficiently that the methane melted and came to the surface? We would have runaway global warming similar to what may have occurred in the great extinctions of the past.
We wonder how there can be extinctions of 80 percent of all ocean creatures. The earth has gone through periods of extensive volcanism. For millions of years, lava flows caused destruction. Humans like optimistic views. But sooner or later, Mother Nature will act up and create catastrophic hazards.
Spector: In light of the potential catastrophes that could befall the United States, where is the safest place?
Coch: I tell my students, New York City. You’re safe in New York because the area isn’t prone to earthquakes, and we don’t have volcanoes. But what bothers me is the trend toward urbanization. Our population is increasing, and our cities are spilling out into hazardous areas. New York City has spilled out onto Long Island, and Long Island has a coastline. Charleston spilled out onto Sullivan’s Island. In Los Angeles, people are moving into the mountains, the most dangerous place for mudflows. And that area also experiences earthquakes and wildfires. It’s a wonder that Los Angeles is still there. The clock is ticking for California. When the USGS says that there’s a 65 percent chance of a movement in 30 years, that’s an extraordinary statement.
We don’t know whether the next earthquake will strike San Francisco or Los Angeles, but look at the consequences. This region has many dormant fault zones and a high potential for major earthquakes. Think about San Francisco in 1906. Were there any airports? Were there nuclear power plants? Were there high-transmission lines, gas lines? In 2014, we have all that infrastructure. Now, consider the consequences for today.
Spector: This has been an eye-opening discussion. Thank you again, Nick, for visiting us here at Verisk and sharing your insights and expertise. I know I’ve gotten an education on some of the key issues surrounding natural disaster management, climate change, and the potential for catastrophic events. We hope our clients have too. We look forward to having you back soon and continuing the discussion.
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