Double disaster preparation: Floods and earthquakes

Dr. Theodore Karasik

One does not usually think of multiple events, such as earthquakes and hurricanes, affecting a single territory. When hurricanes hit land, they turn into tropical depressions, dumping rain rapidly, with areas receiving a year’s worth of rain in a 24-hour period. Subsequently, the deluge runs off dry, parched hillsides into alluvial flows that sweep down canyons, rivers and streams. Overflow is common, and damage can run into hundreds of millions of dollars.
Some observers work with a hypothetical in the nexus between geology and climate change. Indeed, there is concern about a mix of the two in a double disaster based on sheer coincidence, but which could prove devastating. California saw Hurricane Hilary slam into the state at the same time as a 5.1 earthquake was registered in Ojai, north of Los Angeles, on a more dangerous fault than the San Andreas. The fault line has not experienced an earthquake for well over a century and is slated for a “Big One.”
With both hurricane preparation anxiety and earthquake-compounded uncertainty, the event, for some, would be a very uncomfortable experience. California’s recent double event is not unique in this case as weather patterns shift and hurricanes or typhoons increasingly follow new patterns that send such violent weather over heavy urban areas, and infrastructure such as ports and rail. But a big “double whammy” could, in theory, be a devastating economic blow. There are professionals who do forecasting analysis based on hypotheticals and climate change data combined with soil erosion measurements, especially in areas of potential seismic activity. They are warning that climate change and erosion are multipliers of costly damage.
Indeed, the US has examined potential scenarios of a double natural disaster in the American heartland, with rail and road lines knocked out, including dozens of bridges and tunnels. What would be the impact on the US economy? That model is applicable globally as shifting weather patterns and infrastructure, and the geology underneath it potentially become more intertwined. The Pacific Rim countries, for instance, are all vulnerable. One only has to look at Japan’s Fukushima nuclear disaster, which was caused by an earthquake-producing tsunami in 2011. That Japanese earthquake/nuclear double disaster left scientists concerned because of the potential for some type of repeat event.
To be sure, in California, the storm raises safety questions regarding some of the oil refineries that are found in the southern part of the state. None of these units were damaged or thrown offline but there was definitely a unique moment where risk assessment plans overlapped.
Los Angeles-area refineries, with a combined crude oil processing capacity of 1.1 million barrels per day, were preparing for the approach of Hurricane Hilary, the first such storm to menace southern California since 1939. Naturally, earthquake preparation varies from state to state and even from country to country. California has very stringent rules and regulations on earthquake preparation, especially for commercial and business structures. They are also applicable to infrastructure projects. Nevertheless, security officials look at the potential for large quakes combined with flooding, and how that could break many of the logistics lines related to energy production and distribution in the state.
Importantly, the US West Coast is dependent on the region’s refineries and imports from Asia and the Middle East for motor fuel supplies. There are no pipelines connecting California with refining complexes along the US Gulf Coast and in the Middle West. However, that is not all the infrastructure that should be considered. Ports along the coastline bring goods and services from overseas and those products are put on trains for destinations into America’s interior.
Much of this US infrastructure needs to be rebuilt as it is really beginning to age. The geology surrounding the infrastructure that supports such networks increasingly needs to be understood with better science that also accounts for the changing climate. To be sure, the entire scope of infrastructure safety for logistic lines over 30 years old needs to be reevaluated across many susceptible zones, especially those near coastlines where liquefaction of soil would amplify shaking in the event of a quake. Port and rail closures must be part of any risk assessment plan, especially as coastlines begin to bear the brunt of changing weather systems.
This infrastructure runs through rolling hills and mountains that are subject to increasingly heavy storms, and around particular coastlines that are prone to hurricanes of stronger intensity. A large earthquake in the center of the US could cut off transportation and electricity for several weeks, according to scenarios which probably need to be updated given the changing nature of weather. Naturally, geology in terms of earthquakes has its own time scale and activity, but climate change that sends weather systems over areas of extremely loose soils from burning of forests compounds post-disaster recovery.
We have seen other disasters unfold around the world where flooding has forced countries backward and into deeper economic trouble. Pakistan is one country that stands out because of the nature of its floods and how long it has taken to drain the flow and clean up. Luckily, there was no earthquake activity, but up in the mountainous regions anything is possible, and that could have an impact not only on those communities, but also on those downstream. All countries around the world have this problem, so the US and Pakistan are not the sole examples, but only the latest victims of large-scale natural disasters.
Overall, while policy professionals are preparing for climate change and working on the requirements necessary to mitigate dangerous phenomena through international meetings and other necessary activity, the fact is that the Earth is constantly in motion. A better understanding of the double disaster phenomenon would draw attention to a number of areas of concern, including the need for more secure infrastructure and better ways of dealing with the flooding that occurs from storms.