02 Feb 2015:
Many California Farms and
Orchards Idled By Drought, NASA Maps Show
In 2014 — the driest year ever recorded in California — farms and orchards in the state's Central Valley took a major hit
Status of CA farms in 2011 (left) and 2014 (right).
and many agricultural plots were left fallow, as shown in these maps based on NASA satellite data
. The maps depict the status of crop cultivation in California in August 2011 and August 2014. Brown pixels show farms and orchards that have been left fallow, or “idled,” since January 1 in each year. Green pixels show plots where at least one crop was grown during the year. The most recent year with average or above average precipitation across the state was 2011, and, as the map shows, relatively little agricultural land was left fallow that year. In 2014, a much higher proportion of farms and orchards were idle.
26 Jan 2015:
Oil Spills Can Lead to Toxic
Arsenic Water Contamination, Study Says
When petroleum breaks down in underground aquifers, toxic arsenic — up to 23 times the current drinking water
Water sampling at the Minnesota oil-spill test site.
standard — can be released into groundwater, according to
a study by U.S. Geological Survey and Virginia Tech researchers, who analyzed samples collected over 32 years from a petroleum-spill research site in Minnesota. Arsenic, a toxin and carcinogen linked to numerous forms of cancer, is naturally present in most soils and sediments, but is not typically a health concern because its chemical properties keep it bound within soil and minerals. However, certain chemical reactions associated with petroleum contamination and microbial activity in low-oxygen environments, such as in aquifers, change the chemical state of the arsenic so that it can enter the groundwater, researchers say.
22 Jan 2015:
Draining of Greenland Lakes
Signals Massive Melting, Researchers Say
Researchers have discovered
craters left behind when two lakes under the Greenland ice sheet rapidly drained recently — an indication
Crater left after a Greenland lake drained.
that a massive amount of meltwater has started overflowing the ice sheet's natural plumbing and is causing "blowouts" that drain lakes away, they say. One of the two lakes once held billions of gallons of water and emptied to form a mile-wide crater in just a few weeks, researchers report in the journal The Cryosphere
. The other lake, described this week in the journal Nature
, was two miles wide and has filled and emptied twice in the last two years. The researchers suspect that as more meltwater reaches the base of the ice sheet, natural drainage tunnels along the Greenland coast are cutting further inland. The tunnels carry heat and water to areas that were once frozen to the bedrock, potentially causing the ice to melt even faster.
21 Jan 2015:
Filtering Polluted Stormwater
Through Soil Can Protect Salmon, Study Says
Filtering polluted runoff from urban areas through a simple soil mixture dramatically reduced the water's toxic metal and
A pair of coho salmon.
hydrocarbon content and made it safe for coho salmon and the insects they eat, according to new research
. Scientists collected polluted runoff from a four-lane highway in Seattle, then filtered part of the water through a mixture of sand, compost, and shredded bark. Coho salmon and aquatic insects thrived in the filtered stormwater, but they quickly died in the unfiltered water, researchers reported in the journal Chemosphere
. Chemical analyses showed that filtering the water through the soil mixture reduced toxic metals by 30 to 99 percent, polyaromatic hydrocarbons to levels at or below detection, and organic matter by more than 40 percent. The research supports the use of rain gardens and other natural stormwater filtration systems, the authors say.
13 Jan 2015:
California Still in Widespread
Drought, Despite Heavy Precipitation
The heavy rains and snow that fell across much of California in the first half of December did little to recharge the state's
California precipitation deficits
dry reservoirs or ease long-term drought conditions, an analysis
by the National Oceanic and Atmospheric Administration (NOAA) confirms. By the middle of December, 98 percent of the state remained under drought conditions, which is the same portion as before the storms, according to the U.S. Drought Monitor. Dry conditions over the last three years have left the Sierra Nevada mountain range with a 30- to 50-inch precipitation deficit, NOAA reports, and the agriculture-heavy San Joaquin Valley has fared even worse. To bring the state's four-year precipitation total out of the bottom 20 percent historically — a benchmark used to declare drought conditions — every part of the state would need to exceed its average rainfall between now and September.
19 Dec 2014:
'Nuisance Flooding' Will Affect
Most of U.S. Coastline by 2050, Report Finds
By 2050, most U.S. coastal areas are likely to be threatened by 30 or more days of flooding each year due sea level
Nuisance flooding projections for U.S. cities
rise, according to
a new report the National Oceanic and Atmospheric Administration (NOAA). The researchers looked at the frequency of so-called "nuisance flooding," which occurs when the water level reaches one to two feet above local high tide, and found that several cities along the East Coast are already seeing more than 30 days of nuisance flooding each year. Additional major cities — including Baltimore, Atlantic City, Philadelphia, and San Francisco — will reach or exceed that benchmark by 2030, the report says. Although nuisance flooding is not typically catastrophic or dangerous, it is often costly. The report drives home the point, researchers say, that such floods will become commonplace far earlier than 2100, which is generally cited as the date when sea level rise is likely to become damaging.
18 Dec 2014:
Clearing Rainforests Distorts
Global Rainfall and Agriculture, Study Says
Clearing forests not only releases carbon into the atmosphere, it also triggers worldwide shifts in rainfall and temperatures
Global effects of forest loss
that are just as potent as those caused by current carbon pollution and that pose great risk to future agricultural productivity, researchers report
. Deforestation in South America, Southeast Asia, and Africa may alter growing conditions in agricultural areas as far away as the U.S. Midwest, Europe, and China, the study in Nature Climate Change
finds. The researchers calculate that complete tropical deforestation could trigger atmospheric changes leading to an increase of 0.7 degrees Celsius in global temperatures, in addition to warming caused by greenhouse gases released from the deforestation itself. That would double the observed global warming since 1850, the researchers note. They say their findings indicate that many of the predicted changes associated with widespread deforestation are already occurring — from Thailand, which is receiving less rainfall at the beginning of the dry season, to parts of the Amazon, where once-predictable rainfall has shifted notably.
17 Dec 2014:
Obama Protects Alaska's
Bristol Bay From Oil and Gas Development
President Obama yesterday announced protections for Bristol Bay, Alaska
A grizzly bear catches a salmon in Bristol Bay.
of the most productive fishing grounds in the nation, from future oil and gas development. The president's action is expected to benefit commercial fishermen and Native Alaskans and boost conservation efforts in the region, which is roughly the size of Florida. Noting that Bristol Bay is the world's largest sockeye salmon fishery and the source of 40 percent of U.S. wild-caught seafood — a catch worth $2 billion annually — Obama vowed to ensure long-term safeguards for the bay. The region has been under protection intermittently since 1989, when the Exxon Valdez spill prompted a federal moratorium on offshore drilling. "It is a natural wonder, and it’s something that’s just too precious to be putting out to the highest bidder," Obama said in a video message
. The federal government is still considering whether to allow development of what would be North America's largest open-pit mine
in the bay's watershed.
25 Nov 2014:
China’s Lake Ebinur Has Been
Shrinking Dramatically, NASA Image Shows
As this NASA satellite image shows
, Lake Ebinur, located in northwestern China near the border of
Kazakhstan, has shrunk by 50 percent since 1955 as a result of development, agriculture, and natural fluctuations in precipitation. The lake’s saline water is light blue, and the dried lake bed appears white due to salts and other minerals that have been left behind as the water evaporates. The lake’s size fluctuates from year to year due to natural variations in snowmelt and rainfall, and human activity also plays a key role, Chinese researchers say. The nearby city of Bole, with a population of 425,000, consumes significant amounts of water, and farmers irrigate their crops — especially cotton — with water that would otherwise flow into the lake, researchers say. Frequent saline dust storms contribute to desertification, damage soils, harm wetlands, and may be hastening the melting of snow and glaciers downwind, researchers say.
28 Oct 2014:
Scientists Find Seafloor Fallout Plume of Oil from Deepwater Horizon Spill
Researchers say they have found a large fallout plume of oil on the seafloor from the 2010 Deepwater Horizon
Deepwater Horizon oil at the surface of the ocean
disaster in the Gulf of Mexico. According to a report in the Proceedings of the National Academy of Sciences
, a portion of the 2 million barrels of oil thought to be trapped in the deep sea after the spill appears to have settled across a 1,250-square-mile patch of the seafloor centered around the Macondo Well, which discharged an estimated 5 million barrels of oil in the nearly three months between its blowout in April and eventual capping in July. The oil is concentrated in the top half-inch of the seafloor, and mostly distributed in patchy deposits to the southwest of the well, the study found. These deposits account for between 4 and 31 percent of the Macondo oil sequestered in the deep ocean, researchers estimate. The rest has likely been deposited outside this area, they say, but has evaded detection so far because of its patchiness.
27 Oct 2014:
Forests Protect Waterways
From Nitrogen Pollution, Researchers Find
Forest top soils capture and stabilize nitrogen pollution very quickly but release it slowly, according to new research published in the journal Ecology
. The findings indicate that mature forests may be providing an under-appreciated service by storing excess nitrogen, which can lead to algal blooms and oxygen-depleted dead zones if too much is released into lakes and waterways. Older forests store nitrogen more efficiently than young forests recovering from clear-cuts, the researchers found
, because they have accumulated more top soil and organic matter within the forest floor. Previously, it had been unclear how mature forests continued to capture and store nutrients such as nitrogen after they stopped adding tree biomass. The new research indicates it’s likely due to the delay between nitrogen uptake, which happens within days, and nitrogen release, which unfolds over years and decades.
21 Oct 2014:
Desert and Mediterranean Plants
More Resistant to Drought than Expected
Desert and Mediterranean ecosystems may be more resistant to climate change, particularly long-term
Plants in a Mediterranean ecosystem in Chile.
drought, than previously thought, a new study published in Nature Communications
shows. Over the course of a nine-year experiment, researchers subjected plants in four different climatic zones to rainfall conditions predicted under future climate change scenarios. The ecosystems typically received 3.5 to 30.7 inches of precipitation annually, and researchers cut that total by roughly 30-percent to simulate drought conditions. Surprisingly, the researchers found no measurable changes in plant biomass, density, or species composition and richness in any of the four ecosystems over the course of nine generations of plants. The ecosystems already receive highly variable amounts of rainfall and the 30-percent drop likely falls within the plants’ natural "comfort zone," the researchers say, which could explain the unexpected resilience to drought.
26 Sep 2014:
Aral Sea Basin Dry for First
Time in Modern History, Images Show
For the first time in modern history, the eastern basin of the South Aral Sea has gone completely dry, as this
NASA satellite image
captured in late August shows. The Aral Sea is an inland body of water lying between Kazakhstan and Uzbekistan in central Asia. It was once one of the four largest lakes in the world, but it has been shrinking markedly and dividing into smaller lobes since the 1960s, after the government of the former Soviet Union diverted the region's two major rivers to irrigate farmland. One Aral Sea researcher suggested that it has likely been at least 600 years since the eastern basin entirely disappeared. Decreasing precipitation and snowpack in its watershed led to the drying this year, and huge withdrawals for irrigation exacerbated the problem. Water levels are expected to continue to show major year-to-year variations depending on precipitation and snowpack levels, the researcher said.
23 Sep 2014:
Food Security Issues Often
Neglected After Extreme Weather Events
Extreme weather events — the sort likely to arise with increasing frequency as the planet warms — took a heavy toll on Russia and East Africa in 2010 and 2011, in large part because governments and authorities were ill-equipped to address resulting food shortages and other fallout, according to researchers at the University of Oxford. Russia experienced a heat wave that led to food hoarding and price-fixing of staple crops by speculators, according to the report, which was commissioned by Oxfam
. A drought in East Africa in 2010 through 2011 was tied to an uptick in armed conflicts in the region, which interrupted international and domestic aid for six months. Crop prices reached record levels in several markets, including wheat in Ethiopia, maize in Kenya, and red sorghum grain in Somalia, the report notes. Investing in additional health facilities, establishing pre-positioned food supplies, and other tactics aimed at mitigating the effects of future heat waves, droughts, and floods, could help to blunt the effects of climate change on the poorest and most vulnerable populations, the researchers say.
03 Sep 2014:
Mobile Phone Networks Can
Help Monitor Global Rainfall, Study Says
New research shows
that mobile phone networks, which cover 90 percent of the world's population, can help track rainfall events — a task that has proven difficult for both advanced satellite systems
and ground-level observation networks. By compiling data on signal disruptions from mobile phone networks in Burkina Faso in West Africa, a team of researchers was able to calculate with 95 percent accuracy both the location and volume of rain that fell, even during short-lived storms, according to a report in Geophysical Research Letters
. Mobile phone companies maintain detailed records on signal disruptions, which can occur when water droplets block and deflect signals between antennae, to determine whether their networks are functioning properly. By tapping into those records, researchers could distill data on rainfall events at extremely fine spatial and temporal scales. As mobile phone networks expand across the globe, such data could be used to create highly accurate rainfall maps, researchers say, although gaining access to records could prove difficult.
02 Sep 2014:
Six Strategies Could End
Global Water Stress by 2050, Scientists Say
Global water stress could be alleviated by the year 2050 if countries work to implement six key strategies
ranging from building more reservoirs to controlling population growth, according to
research from Canada and the Netherlands. Water stress is defined as occurring when more than 40 percent of the water from a region's rivers is unavailable because it is already being used — a situation that currently affects roughly one-third of the global population. Writing in Nature Geoscience
, the scientists propose six steps they believe can help reduce water stress: planting crops that use water and nutrients more efficiently; using more efficient irrigation methods; improving the efficiency of water use in homes, industry, and municipalities; limiting the rate of population growth so global population stays below 8.5 billion by 2050; increasing reservoir water storage capacity; and intensifying water desalination operations
29 Aug 2014:
New Database Tracks Ecological
Health Impacts of Dams on World's Rivers
A newly launched online database
illustrates the impacts of nearly 6,000 dams on the world's 50 major
river basins, ranking their ecological health according to indicators of river fragmentation, water quality, and biodiversity. The "State of the World's Rivers" project was developed by the advocacy organization International Rivers
and created using Google Earth. Users can compare the health of individual river basins, see the locations of existing and planned dams, and explore 10 of the most significant river basins in more depth. The 6,000 dams represented in the database are a small percentage of the more than 50,000 large dams that impact the world's rivers, the organization notes.
26 Aug 2014:
Meat Production, Especially
Beef, Strains Land and Water, Study Says
Global meat production has expanded more than four-fold over the last 50 years — and 25-fold since
Beef cattle graze in Colombia
1800 — due to growing purchasing power, urbanization, and changing diets, according to a new report from the Worldwatch Institute
. Consumers in industrial countries still eat much larger quantities of meat (75.9 kilograms per person) than those in developing nations (33.7 kilograms), though that gap is beginning to close, the report says. Nearly 70 percent of the planet's agricultural land and freshwater is used for livestock, with additional land and water used to grow grains for livestock feed. Beef production alone uses about three-fifths of global farmland and yields less than 5 percent of the world's protein, according to the report. Sustainable agricultural practices
such as feeding livestock with grasses instead of grains and using natural fertilizers could reduce these impacts, the report notes, but alternative dietary choices hold the most immediate promise for reducing the environmental footprint of meat production.
22 Aug 2014:
Drought in Western U.S.
Has Caused Land to Rise, Researchers Say
The western U.S. has lost so much water during the ongoing severe drought that the land has sprung up by
GPS station in California's Inyo Mountains
as much as 15 millimeters (0.6 inches), according to a study in the journal Science
. Water at the surface of the earth typically weighs down the land, but the region has lost enough water that the tectonic plate underlying the western U.S. has undergone rapid uplift, much like an uncoiling spring, researchers explain. California's water deficit over the past 18 months has caused some of its mountain ranges to rise by more than half an inch, and the West overall has risen by 0.15 inches, according to the study. Using ground positioning data from GPS stations throughout the region, researchers from the University of California, San Diego, estimate the water loss to be 240 gigatons (63 trillion gallons) — equivalent to a nearly four-inch layer of water spread out over the entire western U.S.
14 Aug 2014:
Some Chemicals in Fracking
Fluids Raise Red Flags, Researchers Say
Of the more than 200 compounds used in hydraulic fracturing fluids, eight are toxic to mammals and the
A Marcellus Shale fracking operation
health risks of roughly one-third are unknown, according to
researchers at Lawrence Berkeley National Lab. Hydraulic fracturing, also known as fracking, is a drilling technique that releases natural gas and oil by injecting fluids with chemical additives deep into rock formations. The research team tracked down substances commonly used as fracking additives and found they include gelling agents to thicken the fluids, biocides to inhibit microbial growth, and compounds to prevent pipe corrosion. The industry claims the additives are non-toxic and food-grade, and while that is true in some cases, the researchers note, most fracking compounds require treatment before they can be safely released into the environment. Moreover, a number of chemicals that could pose health risks, such as corrosion inhibitors and biocides, are used in reasonably high concentrations in fracking fluids, the researchers note.
06 Aug 2014:
Western U.S. In Its Quietest
Fire Season In A Decade, Officials Report
The western U.S. is in the midst of its quietest wildfire season
in a decade, according to data from the National
Interagency Fire Center (NIFC). With 1.7 million acres burned through August 4, the 2014 fire season has destroyed well below the average of 4.4 million acres for the previous nine years through the same date. Fire season still has a few months left, however, and the year's good fortune may not last: Above normal fire potential is expected to continue
over most of California, Nevada, Oregon, Washington, and Idaho, according to the NIFC. Average temperatures have been 2 to 4 degrees above normal for most of the West; portions of the western Great Basin, northern California, and Pacific Northwest were 6 to 8 degrees warmer than normal; and exceptional drought conditions continue in California, western Nevada, and the Texas Panhandle, the center says.
04 Aug 2014:
California Takes Steps to
Curb Lawn Watering During Severe Drought
In the midst of a severe, long-term drought, California is taking unprecedented steps to discourage watering of
A drought-resistant yard
residential lawns, with some areas offering residents substantial cash incentives for installing water-saving landscaping, AFP reports
. The "Cash in Your Lawn" program in Los Angeles offers residents up to $6,000 ($3 per square foot) for replacing their lawns with drought-tolerant plants, rocks, and pebbles. Throughout the state, Governor Jerry Brown recently prohibited lawn watering more than two times per week and banned fines for brown lawns, which homeowner associations sometimes impose with the intent of improving a neighborhood's appearance. The drought, currently in its third year, threatens the water supply of California's 38 million residents. Agricultural regions
have already seen severe water reductions, placing extra pressure on the state's groundwater reserves.
25 Jul 2014:
Southwestern U.S. Aquifers
Are Extremely Low, NASA Data Show
Groundwater reserves in the U.S. Southwest are severely low and prospects for their long-term viability are bleak as persistent drought continues to parch the
land and prevent recharging, according to an assessment from NASA
. As shown in this map, many underground aquifers in the Southwest are extremely dry compared to average conditions over the past 60 years. Deep red areas on the map, such as in southern California and Nevada, depict aquifers that are so dry there's less than a 2 percent chance they could have experienced such levels of drought-related depletion since 1948. Although the Pacific Northwest is experiencing drought-related wildfires, its aquifers appear to be well-stocked, according to the map. The discrepancy is likely due to the long lag between dry conditions at the surface and depletion of groundwater reserves, researchers say.
15 Jul 2014:
California Agriculture Relying
Too Heavily on Groundwater in Drought
California's agriculture industry is relying too heavily on groundwater to irrigate drought-stricken farmlands — a trend that will not be sustainable long-term, according
Central Valley orchard
to a study
by the University of California, Davis. The drought, which is the third most severe on record, is responsible for the greatest water loss ever seen in California agriculture, with river water for Central Valley farms reduced by roughly one-third, the study found. Groundwater pumping will likely replace most river water losses, and some areas have more than doubled their pumping rate over the previous year. If the drought continues for two more years, the report says, groundwater reserves will continue to be depleted to replace surface water losses and pumping ability will slowly decrease, which could affect crop production. So far in the current drought, 428,000 acres of cropland — roughly 5 percent — has been made fallow across the Central Valley, Central Coast, and Southern California.
14 Jul 2014:
Human Activity Has Caused
Long-term Australian Drought, Model Shows
A new high-resolution climate model shows that southwestern Australia's long-term decline in fall and winter rainfall, which began around 1970 and has increased over the last four decades, is caused by
increases in man-made greenhouse gas emissions and ozone depletion, according to
research published in Nature Geoscience
. Simulating both natural and man-made climate effects, scientists showed that the decline in rainfall is primarily driven by human activity. Rises in greenhouse gas emissions and thinning of the ozone hole have led to changes in large-scale atmospheric circulation, including a poleward movement of the westerly winds and increasing atmospheric surface pressure over parts of southern Australia. This has led to decreased rainfall, the study said. The drying is most severe over southwest Australia, where the model forecasts a 40 percent decline in average rainfall by the late 21st century, with significant implications for regional water resources.
12 Jun 2014:
U.S. Breweries Cut Water
Use Amid Widespread Drought Conditions
Major breweries in the U.S. are cutting back on the amount of water they use to brew beer as drought threatens their water supplies, the Associated Press
reports. MillerCoors, headquartered in Chicago, has reduced its water use by 9.2 percent since 2012, a company sustainability report said. Earlier this month St. Louis-based Anheuser-Busch, the largest U.S. brewer, reported that it has cut water use by 32 percent in the last five years. Employing strategies such as fueling boilers with wastewater, recycling water used to clean bottles and cans, and installing sensors to fine-tune irrigation in hop and barley fields, MillerCoors has cut water use to 3.48 barrels of water for each barrel of beer, the company says. The company is also giving $700,000 to landowners in the watershed of its Fort Worth brewery who make efforts to curb erosion and runoff by, for example, planting native grasses or rotating cattle grazing lands. Craft breweries typically use twice as much water as major breweries per barrel of beer, the AP notes, because they are smaller in scale and don't have access to the same technology.
11 Jun 2014:
Group Will Pay Farmers
To Create Temporary Migratory Bird Habitat
started by The Nature Conservancy aims to enlist California farmers in creating temporary habitats for migrating birds — a partnership that could become
more important as the state's long-term drought continues and the birds' wetland habitats dwindle. Using crowdsourced data, The Nature Conservancy (TNC) tracks the paths of migratory birds on their annual journey from Canada to South America to determine where and when the birds will need suitable wetland habitat for stop-overs in California's Central Valley. Then, in a sort of reverse auction, TNC asks farmers how much they would charge to temporarily flood their land to accommodate the birds, and pays farmers with the lowest bids to do so for a few weeks or months. The Nature Conservancy says the year-old program has been a success, enabling the organization to rent habitat for roughly 0.5 to 1.5 percent of what permanent protection costs. The program's budget is $1 million to $3 million annually. Forty farmers flooded roughly 10,000 acres last year, and sightings of key migratory bird species were 30 times above average, according to TNC.
21 May 2014:
Trash-scooping Water Wheel
Cleans up Garbage From Baltimore Harbor
A new contraption
in a Baltimore river is helping to clear trash and debris — up to 50,000 pounds of it each day — from the city's Inner Harbor. The 50-foot-long
"water wheel" gathers garbage floating in the Jones Falls River, which runs through the city to the Baltimore Inner Harbor, and deposits it in a large dumpster so the trash can be hauled away. Two large booms funnel debris toward a conveyor belt powered by the wheel, which itself is powered primarily by the flowing river. When the flow isn't strong enough to turn the wheel, water pumps, run by solar panels lining a canopy over the wheel, turn on and push water up to spin the wheel. The water wheel was designed to handle the heavy debris and larger pieces of trash that the river often carries, said its designer, Baltimore-based Clearwater Mills. It began operating earlier this month and cost $750,000, with $500,000 of that contributed by the Maryland Port Administration, Co.Exist reports.
13 May 2014:
Half of U.S. is Experiencing
Some Degree of Drought, Analysis Finds
Half of the United States is in the midst of a drought, a recent analysis
from the U.S. National Drought Monitor found, with nearly 15 percent of the nation in extreme to
exceptional drought. Dry conditions are pushing north rapidly, along with warmer temperatures, and soil moisture and groundwater levels are low far in advance of the agricultural peak demand season, according to the National Drought Mitigation Center. Much of the Southwest and Great Plains regions have been in a persistent drought for several years, and as this map prepared by federal agencies shows, an exceptional drought is currently plaguing parts of those regions. The entire state of California is experiencing some level of drought, much of it extreme to exceptional. Snowpack is at half its typical level in many parts of the West and much of the snow has completely melted before it normally would, researchers say. The map is based on measurements of climate, soil, and water conditions from more than 350 federal, state, and local observers around the country.
02 May 2014:
Fracking May Induce Quakes at
Greater Distance than Previously Thought
Hydraulic fracturing and underground wastewater disposal may trigger earthquakes at tens of kilometers from the wells in which water is injected — a greater range than previously thought, according to new research from seismologists
. In one case, an earthquake
Fracking injection well in Louisiana
swarm in Oklahoma has been linked to a cluster of fracking injection wells up to 50 kilometers (31 miles) away, Cornell University researchers report. So-called "induced seismicity" — when human activity causes tremors in the earth's crust — is gaining attention as reports of earthquakes within the central and eastern U.S. have increased dramatically over the past few years. The rise coincides with increased hydraulic fracturing for oil and natural gas, and the injection of wastewater in deep disposal wells in many locations, including Colorado, Oklahoma, and Texas. According to the U.S. Geological Survey (USGS), an average rate of 100 earthquakes per year above a magnitude 3.0 occurred in the three years from 2010-2012, compared with an average rate of 21 events per year observed from 1967-2000.