USGS News

Northern Alaska Coastal Erosion Threatens Habitat and Infrastructure

Summary: In a new study published today, scientists from the U.S. Geological Survey found that the remote northern Alaska coast has some of the highest shoreline erosion rates in the world

Contact Information:

Ann Gibbs ( Phone: 831-460-7540 ); Paul  Laustsen ( Phone: 650-329-4046 );



This oblique aerial photograph from 2006 shows the Barter Island long-range radar station landfill threatened by coastal erosion. The landfill was subsequently relocated further inland, however, the coastal bluffs continue to retreat. (High resolution image)

ANCHORAGE, Alaska — In a new study published today, scientists from the U.S. Geological Survey found that the remote northern Alaska coast has some of the highest shoreline erosion rates in the world. Analyzing over half a century of shoreline change data, scientists found the pattern is extremely variable with most of the coast retreating at rates of more than 1 meter a year.  

“Coastal erosion along the Arctic coast of Alaska is threatening Native Alaskan villages, sensitive ecosystems, energy and defense related infrastructure, and large tracts of Native Alaskan, State, and Federally managed land,” said Suzette Kimball, acting director of the USGS.

Scientists studied more than 1600 kilometers of the Alaskan coast between the U.S. Canadian border and Icy Cape and found the average rate of shoreline change, taking into account beaches that are both eroding and expanding, was -1.4 meters per year. Of those beaches eroding, the most extreme case exceeded 18.6 meters per year.

“This report provides invaluable objective data to help native communities, scientists and land managers understand natural changes and human impacts on the Alaskan coast,” said Ann Gibbs, USGS Geologist and lead author of the new report.

Coastlines change in response to a variety of factors, including changes in the amount of available sediment, storm impacts, sea-level rise and human activities. How much a coast erodes or expands in any given location is due to some combination of these factors, which vary from place to place. 

"There is increasing need for this kind of comprehensive assessment in all coastal environments to guide managed response to sea-level rise and storm impacts," said Dr. Bruce Richmond of the USGS. "It is very difficult to predict what may happen in the future without a solid understanding of what has happened in the past. Comprehensive regional studies such as this are an important tool to better understand coastal change. ” 

Compared to other coastal areas of the U.S., where four or more historical shoreline data sets are available, generally back to the mid-1800s, shoreline data for the coast of Alaska are limited. The researchers used two historical data sources, from the 1940s and 2000s, such as maps and aerial photographs, as well as modern data like lidar, or “light detection and ranging,” to measure shoreline change at more than 26,567 locations.

There is no widely accepted standard for analyzing shoreline change. The impetus behind the National Assessment project was to develop a standardized method of measuring changes in shoreline position that is consistent on all coasts of the country. The goal was to facilitate the process of periodically and systematically updating the results in a consistent manner.

The report, titled “National Assessment of Shoreline Change: Historical Shoreline Change Along the North Coast of Alaska, U.S.-Canadian Border to Icy,” is the 8th Long-Term Coastal Change report produced as part of the USGS’s National Assessment of Coastal Change Hazards project. A comprehensive database of digital vector shorelines and rates of shoreline change for Alaska, from the U.S.-Canadian border to Icy Cape, is presented along with this report. Data for all 8 long-term coastal change reports are also available on the USGS Coastal Change Hazards Portal

 

Greenhouse Gas Emissions Remain the Primary Threat to Polar Bears

Summary: Greenhouse gas emissions remain the primary threat to the preservation of polar bear populations worldwide. This conclusion holds true under both a reduced greenhouse gas emission scenario that stabilizes climate warming and another scenario where emissions and warming continue at the current pace, according to updated U.S. Geological Survey research models

Contact Information:

Paul  Laustsen ( Phone: 650-329-4046 ); Catherine Puckett ( Phone: 352-377-2469 );



ANCHORAGE, Alaska — Greenhouse gas emissions remain the primary threat to the preservation of polar bear populations worldwide. This conclusion holds true under both a reduced greenhouse gas emission scenario that stabilizes climate warming and another scenario where emissions and warming continue at the current pace, according to updated U.S. Geological Survey research models.  

Under both scenarios, the outcome for the worldwide polar bear population will very likely worsen over time through the end of the century.

The modeling effort examined the prognosis for polar bear populations in the four ecoregions (see map) comprising their range using current sea ice projections from the Intergovernmental Panel on Climate Change for two greenhouse gas emission scenarios. Both scenarios examined how greenhouse gas emissions may affect polar bears: one looked at stabilization in climate warming by century’s end because of reduced GHG emissions, and the other looked at unabated (unchanged) rates of GHG emissions, leading to increased warming by century’s end.

“Addressing sea ice loss will require global policy solutions to reduce greenhouse gas emissions and likely be years in the making,” said Mike Runge, a USGS research ecologist. “Because carbon emissions accumulate over time, there will be a lag, likely on the order of several decades, between mitigation of emissions and meaningful stabilization of sea ice loss.”

Under the unabated emission scenario, polar bear populations in two of four ecoregions were projected to reach a greatly decreased state about 25 years sooner than under the stabilized scenario. Under the stabilized scenario, GHG emissions peak around 2040, decline through 2080, then decline through the end of the century. In this scenario, USGS projected that all ecoregion populations will greatly decrease except for the Archipelago Ecoregion, located in the high-latitude Canadian Arctic, where sea ice generally persists longer in the summer. These updated modeling outcomes reinforce earlier suggestions of the Archipelago’s potential as an important refuge for ice-dependent species, including the polar bear.

The models, updated from 2010, evaluated specific threats to polar bears such as sea ice loss, prey availability, hunting, and increased human activities, and incorporated new findings on regional variation in polar bear response to sea ice loss.

“Substantial sea ice loss and expected declines in the availability of marine prey that polar bears eat are the most important specific reasons for the increasingly worse outlook for polar bear populations,” said Todd Atwood, research biologist with the USGS, and lead author of the study. “We found that other environmental stressors such as trans-Arctic shipping, oil and gas exploration, disease and contaminants, sustainable harvest and defense of life takes, had only negligible effects on polar bear populations—compared to the much larger effects of sea ice loss and associated declines in their ability to access prey.”

Additionally, USGS researchers noted that if the summer ice-free period lengthens beyond 4 months – as forecasted to occur during the last half of this century in the unabated scenario – the negative effects on polar bears will be more pronounced. Polar bears rely on ice as the platform for hunting their primary prey – ice seals – and when sea ice completely melts in summer, the bears must retreat to land where their access to seals is limited. Other research this year has shown that terrestrial foods available to polar bears during these land-bound months are unlikely to help polar bear populations adapt to sea ice loss.

USGS scientists’ research found that managing threats other than greenhouse gas emissions could slow the progression of polar bear populations to an increasingly worse status. The most optimistic prognosis for polar bears would require immediate and aggressive reductions of greenhouse gas emissions that would limit global warming to less than 2°C above preindustrial levels.

The U.S. Fish and Wildlife Service listed the polar bear as threatened under the Endangered Species Act in 2008 due to the threat posed by sea ice loss. The polar bear was the first species to be listed because of climate change. A plan to address recovery of the polar bear will be released into the Federal Register by the USFWS for public review on July 2, 2015.

The updated forecast for polar bears was developed by USGS as part of its Changing Arctic Ecosystems Initiative, together with collaborators from the U.S. Forest Service and Polar Bears International. The polar bear forecasting report is available online

Polar Bear Ecoregions: In the Seasonal Ice Ecoregion (see map), sea ice melts completely in summer and all polar bears must be on land. In the Divergent Ice Ecoregion, sea ice pulls away from the coast in summer, and polar bears must be on land or move with the ice as it recedes north. In the Convergent Ice and Archipelago Ecoregions, sea ice is generally retained during the summer. (High resolution image)

USGS Names New Director of St. Petersburg Coastal and Marine Science Center

Summary: Cheryl J. Hapke begins work this week as the Director of the U.S. Geological Survey’s St. Petersburg Coastal and Marine Science Center Cheryl Hapke Takes Helm of 100-person Science Program This Week

Contact Information:

Cheryl Hapke ( Phone: 727-502-8068 ); Vic  Hines ( Phone: 813-855-3125 );



ST. PETERSBURG, Fla. -- Cheryl J. Hapke begins work this week as the Director of the U.S. Geological Survey’s St. Petersburg Coastal and Marine Science Center.  Located in St. Petersburg, Florida, the center is one of three USGS Coastal and Marine Geology science centers nationwide, and is focused on investigations to understand processes related to changes within coastal and marine environments that have high societal impact. Research programs include those that examine natural hazards, resource sustainability and environmental change.

Hapke received her Ph.D. in coastal geology from the University of California Santa Cruz, an M.S. in geology from the University of Maryland, and a B.S. in Geology from the University of Pittsburgh. She is a research geologist with expertise in coastal-erosion hazards within a variety of geomorphic environments, including rocky coasts, barrier islands and carbonate systems. Her career with the USGS has spanned 18-years and four science centers across the U.S.

“Cheryl’s career path of working at all three USGS Coastal and Marine Geology Program science centers, as well as with the USGS Patuxent Wildlife Research Center, gives her a unique and broad perspective of both USGS and the Coastal and Marine Geology Program goals, objectives, and roles within their respective regions,” said Jess Weaver, USGS Southeast Regional Director. “Her vision is one of unity and integration—from the community level in St. Petersburg to enhanced collaboration and resource-sharing across the multidiscipline science centers in the Southeast Region.”

Hapke’s first priority as the new director is to increase the local visibility of the center in the City of St. Petersburg, as well as throughout the State of Florida and the Southeast.

“Our coastal and marine program is uniquely suited, and we are well-poised, to address critical scientific gaps in our knowledge of physical and ecological coastal hazards associated with storms, sea-level rise and climate change,” she said.

Her USGS career began at the Pacific Coastal and Marine Science Center in Santa Cruz, California, in 1997, where she studied coastal cliff erosion hazards and coastal landslide processes.

In 2005, Hapke moved to the East Coast, where she collaborated with the National Park Service, first through the USGS Patuxent Wildlife Research Center from an office at the University of Rhode Island, and then through the USGS Woods Hole Coastal and Marine Science Center in Woods Hole, Massachusetts. Her research focused on beach and bluff erosion hazards on various U.S. shores, including Fire Island, New York.

In 2011, Hapke transferred to the St. Petersburg Coastal and Marine Science Center, and in October 2012, Hurricane Sandy hit the U.S. east coast. Hapke’s research on Sandy’s impacts on Fire Island has contributed significantly to the broad understanding of how barrier islands respond to and recover from major storms. In the months after Sandy, Hapke served a 3-month detail to the Federal Emergency Management Agency, where she provided expertise in coastal science to numerous federal and New York State agencies as part of the National Disaster Recovery Framework.

Hapke takes over from Dick Poore, who retired in March 2015.

Water Used for Hydraulic Fracturing Varies Widely Across United States

Summary: The amount of water required to hydraulically fracture oil and gas wells varies widely across the country, according to the first national-scale analysis and map of hydraulic fracturing water usage detailed in a new USGS study accepted for publication in Water Resources Research, a journal of the American Geophysical Union USGS Releases First Nationwide Map of Water Usage for

Contact Information:

Anne Berry Wade (USGS) ( Phone: 703-648-4483 ); Leigh Cooper (AGU) ( Phone: 202-777-7324 ); Tanya Gallegos ( Phone: 703-648-6181 );



The amount of water required to hydraulically fracture oil and gas wells varies widely across the country, according to the first national-scale analysis and map of hydraulic fracturing water usage detailed in a new USGS study accepted for publication in Water Resources Research, a journal of the American Geophysical Union. The research found that water volumes for hydraulic fracturing averaged within watersheds across the United States range from as little as 2,600 gallons to as much as 9.7 million gallons per well.

This map shows the average water use in hydraulic fracturing per oil and gas well in watersheds across the United States. (High resolution image)

In addition, from 2000 to 2014, median annual water volume estimates for hydraulic fracturing in horizontal wells had increased from about 177,000 gallons per oil and gas well to more than 4 million gallons per oil well and 5.1 million gallons per gas well. Meanwhile, median water use in vertical and directional wells remained below 671,000 gallons per well. For comparison, an Olympic-sized swimming pool holds about 660,000 gallons.

“One of the most important things we found was that the amount of water used per well varies quite a bit, even within a single oil and gas basin,” said USGS scientist Tanya Gallegos, the study’s lead author. “This is important for land and resource managers, because a better understanding of the volumes of water injected for hydraulic fracturing could be a key to understanding the potential for some environmental impacts.”

This map shows the percentage of oil and gas wells that use horizontal drilling in watersheds across the United States. (High resolution image)

Horizontal wells are those that are first drilled vertically or directionally (at an angle from straight down) to reach the unconventional oil or gas reservoir and then laterally along the oil or gas-bearing rock layers. This is done to increase the contact area with the reservoir rock and stimulate greater oil or gas production than could be achieved through vertical wells alone.

However, horizontal wells also generally require more water than vertical or directional wells. In fact, in 52 out of the 57 watersheds with the highest average water use for hydraulic fracturing, over 90 percent of the wells were horizontally drilled.

Although there has been an increase in the number of horizontal wells drilled since 2008, about 42 percent of new hydraulically fractured oil and gas wells completed in 2014 were still either vertical or directional. The ubiquity of the lower-water-use vertical and directional wells explains, in part, why the amount of water used per well is so variable across the United States.

The watersheds where the most water was used to hydraulically fracture wells on average coincided with parts of the following shale formations:

  • Eagle Ford (within watersheds located mainly in Texas)
  • Haynesville-Bossier (within watersheds located mainly in Texas & Louisiana)
  • Barnett (within watersheds located mainly in Texas)
  • Fayetteville (within watersheds located in Arkansas)
  • Woodford  (within watersheds located mainly in Oklahoma)
  • Tuscaloosa  (within watersheds located in Louisiana & Mississippi)
  • Marcellus & Utica (within watersheds located in parts of Ohio, Pennsylvania, West Virginia and within watersheds extending into southern New York)

Shale gas reservoirs are often hydraulically fractured using slick water, a fluid type that requires a lot of water. In contrast, tight oil formations like the Bakken (in parts of Montana and North Dakota) often use gel-based hydraulic fracturing treatment fluids, which generally contain lower amounts of water.

This research was carried out as part of a larger effort by the USGS to understand the resource requirements and potential environmental impacts of unconventional oil and gas development. Prior publications include historical trends in the use of hydraulic fracturing from 1947-2010, as well as the chemistry of produced waters from hydraulically fractured wells.

The report is entitled “Hydraulic fracturing water use variability in the United States and potential environmental implications,” and has been accepted for publication in Water Resources Research. More information about this study and other USGS energy research can be found at the USGS Energy Resources Program. Stay up to date on USGS energy science by signing up for our quarterly Newsletter or following us on Twitter!