Why Chile Has So Many Earthquakes & Tsunamis

The Magnitude 8.2 quake that struck off the coast of Chile on April 1, 2014, was the latest in a series of major earthquakes and tsunamis to hit that area in recent years. The undersea quake and resulting 7 ft. (2.1m) tsunami killed 7, toppled buildings, and severely damaged the Chilean fishing fleet.  Earthquake/tsunami events in 2010 (M8.8), 2007 (M7.7), 2005 (M7.8), and 2001 (M8.4) killed more than 1,000 and inflicted billions of dollars in property damage .

The most powerful earthquake ever recorded, a Magnitude 9.5, hit the coast of Chile on May 22, 1960. The monster quake triggered an 82 ft (25m) tsunami that not only battered the west coast of South America, but rolled across the Pacific Basin, devastating Hilo, Hawaii, and damaging coastal villages as far away as Japan and the Philippines. Some sources estimate 6,000 dead and $800 million in property loss (6 billion in 2014 dollars).

Why does this area of planet earth spawn so many high-magnitude earthquakes and punishing tsunamis?

One explanation is that the collision of the two tectonic plates that meet off the South American west coast occurs, in geologic terms, at a very high rate of speed. The oceanic Nazca Plate and the continental South American Plate converge in the Peru-Chile trench that lies about 100 mi (160km) off the coast. The overriding South American Plate moves eastward at 10cm a year, while the subducting Nazca Plate pushes west at 16cm/y, a closing velocity of 26cm/y (about 10 in.), one of the fastest absolute motions of any tectonic plate. The Africa Plate, for example, moves approximately 7 times slower.

This high closing velocity builds up fault line strain much faster than it does when slower-moving plates converge. Every few years, tension on the Peru-Chile fault line builds up to a breaking point. In this latest earthquake on April 1, a 100 mi. (160km) section of the fault line ruptured, allowing the Nazca Plate to ram under the South American Plate. This sudden violent action 12.5 mi (20.1km) below the ocean floor triggered the tsunami and the 8.2 earthquake, and at the same time wedged the South American Plate higher. Uplifting from frequent fault line failures continues to build the Andes Mountain Range into one of the highest in the world. During the 1960 M9.5 quake, some coastal areas uplifted as much as 10 ft. (3m).

As long as the two tectonic plates that meet off the South American coast move geologically at such high speed, major earthquakes and tsunamis will keep happening. We hope the zoning laws and building codes put in place by the governments of Chile and Peru will keep the damage and loss of life to a minimum.  

Why Did the Hill Come Down?

As of this writing, 21 people have been confirmed dead and 30 are missing in the disastrous March 22, 2014, Oso, Washington mudslide. We send our condolences to all those affected by this terrible tragedy.

At the same time, we have to ask ourselves why a forest-covered mountainside would suddenly shear off and bury an entire community of 30 homes under a 1 square mile (2.6km²) mud and debris slide 40 ft (12m) deep.

Two main reasons have been given. One is that the hill had become saturated after weeks of heavy rainfall. The rainfall in that area during the month of March was 200% of normal. Although the soil there is compacted clay that tends to be impermeable, it is believed there were cracks at the top that allowed the rain to penetrate. The other reason for the failure is that the swollen Stillaguamish River at the base was undercutting the toe of the hill. With the base of the hill weakened and the slope heavy with soaked-in rain, the hill collapsed.

After a number of landslides had been reported in that area during the prior 40 years, the US Army Corps of Engineers did a survey there in 1999 and issued a report warning of “the potential for catastrophic failure.” In 2006, a section of that same hill collapsed and blocked the course of the river. Other state and local agencies had examined the hill at various times and all concluded it was unstable. Whether the permit-issuing authorities were aware of those findings is not known. What is known is that building permits for that location continued to be issued, even after the 2006 slide.

The last compilation of world landslide statistics was posted by the American Geographical Union for the year 2010. In that year, 6,211 people died in 494 landslide events worldwide. 83,275 landslide deaths were reported for the period September, 2002 to December 2010, an average of a little more than 10,000 a year. People living in the mountains of China, India, Central America, the Philippines, Taiwan, and Brazil were the most vulnerable during that period. Landslides and mudslides often occur when intense rainfall from tropical storms and monsoons saturate hillsides that have been compromised by logging, farming, and construction. Although not as highly dramatic as earthquakes and tsunamis, landslides may be the most costly of all natural disasters in loss of life and property.

In the United States, landslide fatalities average between 25 and 50 a year, according to the Centers for Disease Control and Prevention. Using airborne Lidar, a laser-based mapping system, it is now possible to set up a national data bank on areas throughout the US that are susceptible to hillside failure, but it would be a long and very costly project. Until such a survey is done, local jurisdictions will have to rely on other methods to determine landslide-prone areas. Even knowing the possible dangers, people will still build homes below unstable hillsides, in fire areas, and flood plains. It is up to local zoning authorities to prohibit building in these hazardous places.

 

 

Offshore Wind Farms

Constant winds in coastal waters make offshore wind farms highly productive. Most offshore wind turbines are installed on pilings in shallow waters within a few miles of the shoreline, but there are some on floating platforms farther offshore.

The United Kingdom’s 20 offshore wind farms supplied 10% of that nation’s total electrical power production in January, 2014, and 11% in February. Britain is the world leader in number of wind farms located in coastal waters, and in total amount of energy produced. Germany, Netherlands, Denmark, Belgium, and Sweden are close behind with another 58 offshore wind farms, and dozens more under construction or in the planning stage. Offshore wind farms are projected to produce 4% of total European power by 2020, and 15% by 2030.

The US leads the world in amount of energy produced by wind turbines: 120 billion kilowatt hours in 2013, representing more than 4% of US energy production. However, all US wind farms are currently land based. At this time, the US has no offshore wind farms. Plans are on the drawing board and permits have been granted for offshore wind farms in Massachusetts, New Jersey, Rhode Island, and Oregon, but so far no construction work has started. Reasons given are reluctance to increase the cost to the rate payer, and NIMBY (not in my backyard) campaigns by homeowners and environmental groups.

The US Atlantic and Gulf coasts provide more suitable sites for offshore installations than the Pacific Coast, because of a longer and shallower slope out to the edge of the continental shelf. In some areas, shallow waters extend out as far as 200km (160 mi) on the Atlantic coast. The continental shelf drop-off to deep water on the Pacific coast is steeper and more abrupt and not as suitable for shallow water farms. A Seattle company has obtained a lease from Dept. of Interior for 15 square miles of federal waters off Coos Bay, Oregon, for a wind farm on floating platforms anchored by cable to the ocean floor.

Could a massive offshore wind farm project also serve as a buffer against hurricanes and storm surges? Yes, according to a study by Mark Jacobson, professor of civil and environmental engineering at Stanford, and two co-authors, published in the journal Nature Climate Change. In the study, the researchers used computer simulations of Hurricanes Katrina, Sandy, and Isaac to determine the effect of massive offshore wind farms on wind speed and storm surge. In the case of Katrina, the researchers found that an array of 78,000 turbines in coastal waters would have reduced wind speed at landfall 65% to 78%, and storm surge by 79%. Similar results were obtained for Sandy and Isaac. It is not likely that 78,000 turbines will ever be installed offshore in one farm, but if that had been the case, and if the researchers’ conclusions are correct, it would have brought Katrina’s wind speed down to 28 to 44 mph from 125 mph, saved thousands of lives, and $100 billion in Gulf Coast reconstruction. Also, that many turbines would be producing millions of megawatts of clean power. It’s something to think about.  

 

 

 

 

 

 

Sun, Wind, & Fresh Water

Converting ocean water into fresh water is energy intensive, and therefore expensive. Saudi Arabia is a desert kingdom with plenty of oil but very little fresh water. The Saudis burn 1 million barrels of oil a day to produce 60% (4 billion cubic meters) of its total fresh water supply through desalination. If exported onto the world market, those 1 million barrels of oil would bring Saudi Arabia $115 million a day, but it is worth it to them to forgo the profits and have the fresh water. From an environmental standpoint, burning 1 million barrels of oil a day sends close to a half million tons of CO2 emissions into the atmosphere every day, contributing greatly to the pace of global warming.

To deal with these problems, the Saudis have joined with IBM to build a series of solar-powered desalination plants that could by mid-century produce a large share of the kingdom’s water needs.

However, the largest solar-powered desalination plant yet designed will be built in the United Arab Emirates. The Ras Al Khaimah plant, scheduled to start production in 2015, will produce 100,000 cubic meters (approx. 22 million gallons) of fresh water a day, and in addition, provide 20 megawatts of electrical power daily. The developers estimate they will be able to deliver water at a cost of $0.75 per cubic meter. Average cost per cubic meter of water delivered to households in the United States runs between 0.35 and 0.40. Most of the desalination plants run by solar energy are situated in the Middle East where there is an abundance of year round sun and a scarcity of water.

The largest desalination plant run by wind power is near Perth in Western Australia. The Kwinana Desalination Plant produces 144,000 cubic meters of water a day (approx. 38 million gallons), about 17% of Perth’s water supply. The Kwinana plant is powered by the 80 Megawatt Emu Downs wind farm located 200 miles away. Because electrical power has to be supplied evenly 24/7, and because the wind stops blowing from time to time, the power from the wind farm goes into the grid on a trade-off basis. The wind farm contributes 270 Gigawatt hours a year into the power grid, more than offsetting the 180 Gigawatt/h year required to operate the desalination plant. There are a number of smaller desalination plants run by wind-generated electrical power that goes directly from the wind farm to the plant, but Perth has opted for the offset arrangement.

Most desalination plants are still operated with grid power generated by coal, oil, or natural gas because it is less expensive than spending hundreds of millions to construct solar arrays or wind farms. For example, Australia’s other desalination plants providing fresh water to Sydney, Melbourne, Adelaide, and other coastal areas use fossil fuel power from the grid. But more and more, new desalination plants around the world are being planned to operate on alternative power. At some point in the future, all our electricity will have to come from those sources.

 

Crazy Weather & Global Warming

In the first 6 weeks of 2014, the world spawned some of the most severe weather in hundreds of years, including record snowfall in the Midwest and Great Lakes, record cold in the US northeast, ice storms in the southeast, record drought in the southwest, record flooding and windstorms in the UK, unseasonal warming in Scandinavia and Russia, record snowfall in the southern Alps, record flooding in Italy, and record heatwaves and wildfires in Australia, Argentina, and Brazil.

Despite the record snow, ice, and freezing temperatures in some areas, the world continued its long term upward warming trend. NOAA reported that 2013 was tied with 2003 as the warmest year on record. What’s going on?

According to a paper presented this month at a meeting of the American Assn. for the Advancement of Science in Chicago, a weakening jet stream caused by Arctic warming is a possible cause. The polar jet stream is a high-altitude air current with wind speeds of 100 to 120 mph (160 to 200kph) that acts as a weather conveyor belt. When Arctic temperatures stay cold, the jet stream blows stronger and tends to stay in place, bringing normal winter weather to North America, Europe, and Asia.

In January, 2014, the air temperature over the Arctic Ocean was 2 to 4˚C (4 to 7˚ F) higher than average, and 7 to 8˚C (13 to 14˚ F) higher than average over Greenland and Alaska. As the Arctic warms, the jet stream weakens and begins sinking south of its polar route. At the same time, Arctic sea ice is melting at a record rate, exposing more ocean to the rays of the sun. The warmer ocean water in turn accelerates Arctic warming. More rapid evaporation pumps extra moisture into the atmosphere.

A sinking jet stream carries the moisture-laden high-altitude cold Arctic air south into the Midwest and southeast, and across the Atlantic to Europe. While southern Europe is experiencing record rains and snowfall, northern Europe, normally very cold in January and February, is basking in abnormally warm temperatures. With the glaciers and polar ice caps melting at a record rate, sea ice contracting, and oceans warming, it seems obvious that global warming is here, and to some extent driving the world’s current radical weather patterns. The weather will become more radical and storms more intense as the earth gets warmer.

But what is driving global warming? The UN’s International Panel for Climate Change (IPCC) has concluded from all available scientific evidence that it is 95% likely that most of the rise in global temperature since the middle of the 20th Century is due to emissions of greenhouse gases, deforestation, and other human activities.

If greenhouse emissions continue at their present rate the IPCC computer models predict our planet will warm 5˚C (9˚ F) by 2100, and by 10˚C (18˚F) during the following century. The earth is now warmer than it has been since the end of the last ice age 11,300 years ago. If we don’t drastically reduce our carbon-based emissions and start relying more on alternative fuels, are we headed for another ice age? Or another age hot enough for dinosaurs?

 

 

 

 

 

 

Natural Disasters 2013 Review

According to figures released by the German Reinsurer Munich Re, twice as many people died in natural disasters in 2013 than in the prior year, but property damage and insurance losses were significantly less.

Munich Re reports 880 natural disaster events in 2013, costing $125 billion in total losses, compared to $173 billion in 2012, and insured losses of $31 billion, about half the insured costs in the year before. However more than 20,000 people died in natural disasters in 2013, twice the number of deaths reported for 2012. Here are some of the most costly natural disasters of 2013, in either lives or property losses.

Earthquakes: Magnitude 7.0 to 7.7 quakes struck China in April, Pakistan in September, and the island of Bohol in the Philippines in October, killing 1,300 and destroying tens of thousands of homes. Damage amounts were not available.

Tornadoes: On May 20, an EF-5 tornado with a wind speed of 210 mph (340 km/h) ripped through the town of Moore, Oklahoma. The tornado, 1.3 miles (2km) wide, stayed on the ground for 40 minutes on a 17-mile (27km) path of destruction. 1150 homes were wiped out, 91 people died, including 7 children in a local school. Total damage was more than $2 billion.

Floods: Flooding in India, Central Europe, Canada, Mexico, and Colorado resulted in a combined death toll of 7,000 and damages exceeding $30 billion. European flooding was called the worst since the middle ages. Most of the deaths occurred in flash floods and landslides in the mountains of northern India and Nepal.

Meteor strike: A 13,000 ton meteor traveling at 60 times the speed of sound streaked into earth’s atmosphere on Feb. 15 and exploded in a fireball over the Caucuses region of Russia. The shock wave damaged 7,200 buildings and injured 1,500 people. The injuries were mainly from flying glass from blown-out windows. Fortunately, there were no reported deaths.

Wildfires: Brush fires in Australia and California scorched hundreds of thousands of acres. In October, Australian firefighters fought 66 brush fires along a line that stretched for 1,000 miles (1,650km). In California’s Sierra Nevada Mountains, the Rim Fire that started in August was not put out till mid October, after burning 257,000 acres of heavily forested watershed.

Typhoons: Super Typhoon Haiyan struck the Philippines island of Leyte on November 8 with wind speed of 195 mph (320km/h), the strongest ever recorded for a tropical cyclone making landfall. A 20-ft (6m) tidal surge wiped out the city of Tacloban. More than 6,000 people lost their lives in the storm. Total cost has been estimated at up to $15 billion.

While the Pacific typhoon season was quite active, with 31 tropical storms, of which 13 were typhoons and 5 were super typhoons, the Atlantic hurricane season was much quieter than expected, with no major storms. The first few weeks of 2014 have also been relatively quiet, with the exception of the Mt. Sinabung volcano eruptions in Indonesia, during which 14 people have died and 20,000 have been evacuated.  Inevitably, there will be more natural disasters in the months ahead. We will have to wait and see what the rest of 2014 will bring.