Do Earthquake Warning Systems Really Work?

On August 24, 2015, a warning horn blared in a lab at UC Berkeley 10 seconds before the shaking started.  The ShakeAlert system had picked up the Napa Valley 6.0 earthquake 10 seconds before arrival of the main shock. The lab’s instruments accurately displayed the arrival time and strength of the coming quake. But is 10 seconds enough time to react and seek safety? Maybe enough time to scramble under a table to avoid falling objects. Or not step into an elevator.

The amount of advance warning depends on distance from the epicenter. The farther from the epicenter, the more warning time given. Berkeley is about 25 miles (42km) from the Napa Valley fault line rupture site.

The ShakeAlert system is currently under development by a team of seismologists from UC Berkeley, Caltech, U. of Washington, and the USGS. It is undergoing testing in California, where 400 sensors have been installed along the state’s fault lines. The developers have requested funding to add more sensors before the system is put into full operation.

ShakeAlert is based on an earthquake early warning system that has been operating in Japan since 2007, employing automatic warning signals for mobile phones, radio, TV, and the internet. When the magnitude 9.0 earthquake and tsunami hit Japan in 2011, a teacher in a school in Sendai, the largest city near the epicenter, received a 32-second advance warning signal on his mobile phone. He immediately had the class take shelter under their desks. After the severe shaking was over, he evacuated the class to safer ground and no one was injured. Unfortunately, there is not yet an early warning for a tsunami, and that is what did most of the damage.

Earthquake early warning systems are based on the lag time between three seismic waves that occur when a fault line ruptures. The first is a compression wave called the Primary Wave or P Wave. The P Wave is fast, traveling through granite at 5,000 meters per second. The second wave or S Wave is slower, traveling at about half the speed of the P Wave. The even slower Surface Wave arrives last. The S Wave and the Surface Wave are the big shakers that do all the damage.

To quote a USGS article posted on Sept. 11, 2014, “When an earthquake occurs, both compressional P Waves and transverse S Waves radiate outward from the epicenter. The P Wave, which travels fastest, trips sensors causing alert signals to be sent ahead, giving people and automated electronic systems time (seconds to minutes) to take precautionary actions before damage can begin with the arrival of the slower but stronger S Waves and late-arriving surface waves. Computers and mobile phones receiving the alert message calculate the expected arrival time and intensity of the shaking at your location.”

Once the ShakeAlert system is operating successfully in California, the USGS plans to install the system in all earthquake-prone areas across the US. Since this author lives less than 5 miles (8km) from the southern San Andreas Fault where the Big One is expected, the sooner the system is rolled out the better.

 

Water For a Dry Southwest

For generations the Colorado River has supplied water to homes, farms, and industry in Arizona, California, Colorado, Utah, Nevada, New Mexico, and Texas. Now a 14-year drought, climate change, a growing population, and overuse are drying up the Colorado. The water levels in Lake Powell, the reservoir behind the Glen Canyon dam on the upper Colorado, and Lake Mead, the reservoir behind Hoover dam on the lower Colorado, have dropped to all time lows.

In California, the snowpack in the Sierra Nevada was 10% of normal in the winter of 2013-14. Water deliveries to farmers in the San Joaquin Valley, where 65% of the nation’s fruits and nuts are grown, were drastically reduced. Ground water supplies are also declining due to over-pumping. Water shortages are threatening to curtail the region’s $44 billion annual agricultural production.  

Water use restrictions have been imposed throughout the region, but even the strictest rationing can’t make up for the enormous loss of basic water supply. A number of ideas have been proposed for supplying additional water to the parched Southwest. Some appear less practical than others, but all are receiving new consideration.

Alaska to California Pipeline. In the 1990s, the then-governor of Alaska proposed construction of a 2,000 mile (3,218km) undersea pipeline from river sources in southern Alaska to the Shasta reservoir in Northern California. The congressional Office of Technical Assessment estimated the cost of construction at $150 billion in 1990 dollars. Most experts consider the plan unfeasible due to cost and engineering challenges.

Missouri River Pipeline. A proposal to run a 600 mile (965km) pipeline from the Missouri River to Denver has been considered by Interior’s Bureau of Reclamation. Interior Secretary Ken Salazar at the time of the proposal opposed the idea due to high construction cost, to keeping water levels on the Missouri and Mississippi high enough for navigation, and because of political opposition from environmental groups.

Converted Oil Tankers. Single-hulled oil tankers were mothballed when new laws mandated double-hulled vessels for transporting oil in 1993. A proposal to sanitize the tanks on the single-hulled tankers and use them for transporting water from Alaska to California has been floated, so to speak. The expense of bringing the ships out of mothballs, sandblasting the tanks; and fuel, crew, and maintenance costs would make it impractical to deliver fresh water by this method at an affordable price, according to those who have studied the idea.

Giant waterbags. A California company is building flexible fabric barges designed to carry more than a million US gallons of fresh water. Since fresh water is lighter than salt water, these huge waterbags will float when full, and a train of 4 or 5 of them can be towed by a vessel the size of a tug. They are built to withstand almost any weather. A train of such bags can deliver 4 to 5 million gallons of water at a cost lower than water delivered by pipeline or aqueduct, according to the builders. The bags have been used for delivering water successfully from Turkey to points in the Mediterranean, but have not yet been used on the US west coast.

Desalination. This process uses large amounts of fuel to pump seawater through filters to extract the salt. However, several of the US national labs have been researching ways to make desalination more efficient and cost effective. Fresh water supplied by the Israeli-designed plant under construction near San Diego will cost about twice as much as water from the California Aqueduct, but supplies of aqueduct water are being cut back.

The three most practical approaches at this time seem to be more efficient desalination, towing waterbags from surplus-water areas to places that need the water, or living with water rationing. People living in drought areas will have to decide.   

 

 

Siberian Mystery Holes

In September, 2013, people living in the Yamal district of Siberia, where the ground is frozen year round, reported seeing smoke rising from a patch of nearby permafrost. On September 27, 2013, the patch exploded and a crater measuring 30m (98 ft) wide and 70m (230 ft) deep appeared. Scientist Marina Liebman of the Russian Academy of Sciences believes the explosion was caused by methane, the main component of natural gas, building up and compressing inside a subsurface pocket.

Two additional holes in the Siberian permafrost were reported in July, 2014. The new holes are as deep as the first, 70 to 90m (200 to 300 ft), but had smaller openings – diameters of 15m (49ft) and 4m (13 ft). The prevailing theory is that global warming is causing thawing of the Siberian permafrost in spots. The thawing permafrost releases methane, a product of the billions of tons of decomposing organic material that has been trapped beneath hundreds of feet of frozen earth for thousands of years. The methane rises through cracks in the earth and into air pockets just below the surface.

Blasts of methane gushed into the air when the pockets erupted, causing the methane content in the regional atmosphere to rise. There has been some speculation that methane will continue to pour out of these holes, that more holes will appear, and that the “dragon’s breath” of escaping methane will load the atmosphere with methane, which is 20 times stronger than CO2 in trapping radiation and heating the planet. Air content measurements taken since the eruptions show a slight rise in methane, but nothing alarming, putting the doomsday speculation into question.

Nevertheless, the arctic is warming at the rate of 0.5C (0.9F) every 10 years, a faster pace than anyplace else on earth. Because of this rapid rate of warming, most scientists anticipate a gradual increase in thaw rate and the escape into the atmosphere of greater amounts of methane.

How fast and how much is a matter under study. It depends largely on how soon the people occupying our planet can reduce their dependence on fossil fuels. If we continue to pour billions of tons of carbon dioxide into the air every year by burning ever increasing amounts of oil, gas, and coal, the added methane in the atmosphere could heat the planet beyond anything previously experienced by mankind. On the other hand, by cutting back on the burning of fossil fuels, and replacing them with wind, solar, thermal, and other forms of renewable energy, we may be able to stave off the coming of a super hot earth.     

July, 2014 – Bad & Not So Bad

Four natural disasters struck different parts of the world in the first half of July, 2014. One was quite destructive, causing multiple fatalities, injuries, population displacement, and considerable property damage.  The other events, though serious, with some injuries and property loss, could have been worse. But all served as reminders that major catastrophes have struck these areas in the past, and will do so again in the future.

July 15 – Typhoon Rammasun, a Category 3 Tropical Cyclone with winds gusting to 170 km/h ((106 mph), swept across the island of Luzon in the Philippines. 38 people died in the storm, 25,000 homes were damaged or destroyed, over a half million people took refuge in evacuation centers, and 2 million homes lost electrical power. Rice, corn, and other crops suffered $15 million in losses due to flooding. Typhoons causing much greater devastation have hit the Philippines many times in the past, including Super Typhoon Haiyan that struck the southern Philippines in November, 2013, killing more than 6,000.

July 11 – Japan Earthquake. At 4:22 am local time, a magnitude 6.8 earthquake struck off Japan’s northeast coast near Fukushima, site of the devastating 9.0 megathrust quake and tsunami of March, 2011, that wiped out villages, killed 19,000, and knocked out the Fukushima nuclear power plant. 100,000 people who were evacuated at the time are still unable to return to their homes because of radiation contamination. Authorities reported only one injury and no significant damage from the recent July 11 quake. 8 coastal towns in the area issued an evacuation advisory causing thousands of people to move to higher ground. The advisory was cancelled 2 hours later when the tsunami wave created by the earthquake turned out to be only 20cm (8 in) high.

July 7 – Mexico/Guatemala Earthquake. At 6:23 am local time, a magnitude 6.9 quake rattled southern Mexico and Guatemala, killing 3, injuring 35, and causing widespread property damage. The quake epicenter was on the Pacific Coast in a seismically active area that has spawned 12 quakes of magnitude 7.0 or higher in the past 100 years. In 1985, a quake registering 8.1 with its epicenter off the Pacific Coast in the same general area caused extensive damage and loss of life in Mexico City 220 miles (350km) away. The official death toll for the 1985 quake stands at 10,000, but other sources estimate fatalities could have been as high as 40,000.

July 3 – Hurricane Arthur, the first named storm of the Atlantic Hurricane season, made landfall in North Carolina with a sustained wind speed of 100 mph (155km/h). Classified a Category 2 storm, Arthur weakened as it travelled north, moving ashore again in New England as a tropical storm, bringing flooding and power outages. No deaths or injuries directly related to the storm were reported. However, Arthur was a reminder that far deadlier hurricanes have hit the US East Coast in the past, such as Sandy in 2011, and will again at some future time..

The motto for all these areas vulnerable to natural disasters should be the same as that of the Boy Scouts: Be Prepared.        

 

Can We Feed 9 Billion?

One billion people on this planet suffer from chronic hunger. With world population projected to increase from the present 7 billion to 9 billion by 2050, will there be enough food to go around, or will even more human beings go chronically hungry? Chronic hunger means a basic lack of calories and protein to sustain human health. One-third of the children in developing countries now experience stunted growth, and malnourished people are far more susceptible to disease.

According to the Food & Agricultural Organization of the UN (FAO), if population increases to 9 billion, food production will need to rise by 70%, and in the developing world it will need to double. The projected increases in food production will have to overcome rising energy prices, growing depletion of ground water, loss of farmland to urbanization, and increased drought and flooding due to climate change.

Other challenges include a rising middle class in China, India, and other parts of the developing world. As disposable income increases, demand for meat products goes up. Raising cows, pigs, and chickens requires multiple pounds of feed for each pound of meat produced. That means a huge increase in demand for grain, water, and land.

Agriculture is a major emitter of CO2, methane, and nitrous oxide, pumping more greenhouse gasses into the air than all our cars, trucks, trains, and airplanes combined. With ramped-up food production, those emissions will increase even more just as the world is trying to reduce the volume of greenhouse gasses going into our atmosphere.

More efficient farming will be needed to overcome these problems. To Big Ag (companies such as DuPont, Monsanto, John Deere, and Archer Daniels Midland), efficiency means using advanced farming techniques with the latest innovations in fertilizer, equipment, and genetically modified seed to produce more food per acre or hectare. However, UN’s FAO believes the answer lies in helping small farmers in developing countries improve production locally by preserving natural resources and practicing better organic farming methods. This includes reduced tillage to save soil (wind blows tilled topsoil away), crop rotation to save soil nutrients, and improved seeds to save water. Rather than use genetically modified seeds, FAO recommends using traditional breeding methods to develop seeds that need less water, produce more, and resist pests and disease.

It seems that both approaches will be needed if the world is to meet the challenge of feeding 9 billion people a healthy diet, including those who now suffer from chronic malnutrition.  

 

Rising Seas, Sinking Land, & Flooded Cities

Oceans are warming and expanding in volume. Glaciers are melting at a rapid pace around the world. The Greenland Ice Sheet is losing mass at an alarming rate. The West Antarctica Ice Sheet is eroding and could eventually collapse from ocean water heated by thermal vents recently discovered underneath it. This all adds up to a projected sea level rise of up to 3.3 ft. (1m) by 2100, and possibly more, depending on how fast the Antarctic Ice Sheet melts.

What does this mean for low-lying cities along the US coastlines? Based on studies by USGS, NOAA, National Climate Assessment, and several university research teams, the cities most at risk are located along the Atlantic seaboard from Boston to Florida.

A 2012 study by USGS concludes that sea levels along the US east coast will rise 3 to 4 times faster than the global average during the balance of the 21st Century. While sea levels worldwide are projected to rise 2 to 3.3 ft. (0.7m to 1m) by 2100, they are expected to surge more than 6 ft. (1.8m) along the Atlantic coast. The USGS study and the 2013 National Climate Assessment named Boston, New York, Norfolk, and Miami as the large population centers most vulnerable to sea level rise flooding.

Boston. A University of Massachusetts Boston study indicates that a 2 ft. (0.7m) sea level rise by 2060 would mean twice a day flooding in the lower parts of Boston. During hurricanes, storm surges could flood 30% of the city, including Back Bay and the Harvard campus. The design firm Sasaki Assoc. concludes that approximately 200,000 residents, 89,000 housing units, and $8 billion in property values are vulnerable to flooding during a major storm surge.

New York/New Jersey. The flooding that occurred during Hurricane Sandy is an example of what can happen when rising sea levels combine with a major storm surge. Lower Manhattan and parts of the New Jersey coast suffered severe flood damage when the storm surge overtopped Manhattan’s seawall and powerful waves washed far inland along the Jersey Shore.

An additional problem for most of the mid-Atlantic coast is land subsidence. As sea levels continue to rise, the land is gradually sinking, so that even small sea level changes can result in major damage. When the glaciers that once covered the area retreated after the last Ice Age, the land that had been compressed by the weight of the glacial ice gradually rose, while adjacent land such as the seacoast that had been squeezed higher started to sink. That process has continued for hundreds of years and shows no sign of stopping. Islands in Chesapeake Bay that once stood well above the water line have disappeared over the past 50 years as the bottom sinks and the water level rises.

Norfolk. The land in Norfolk and Virginia’s Tidewater region is sinking especially fast, causing streets throughout the area to flood even during normal high tides. The city is spending millions to raise streets and improve drainage. A long-term fix could cost $1 billion, money the city doesn’t have. The mayor acknowledged that some areas might have to be abandoned.

Miami. The low-lying greater Miami area, with a population of 5.7 million, is one of the worldwide communities most at risk from sea level rise flooding. Miami Beach, at an elevation of 4.4 ft. (1.3m), is already seeing frequent salt water street flooding at high tide. Miami is exceptionally vulnerable because it is built on top of porous limestone, which is allowing the rising sea level to soak into the city’s foundation, bubble up through pipes and drains, encroach on fresh water supplies, and saturate infrastructure. According to the US Government’s National Climate Assessment, the sea level around Miami could rise up to 2 ft. (0.7m) by 2060. Broward County officials estimate a 1 ft. (0.3m) sea level rise will threaten $4 billion of south Florida’s property base.

Most low-lying east coast communities are working on flood mitigation plans. Some are more advanced than others. We hope they complete those plans and put them in place in time to keep their cities dry.