General view of a 35-meter-high riverbank exposure of the ice-rich syngenetic permafrost (yedoma) containing large ice wedges along the Itkillik River in northern Alaska. Copyright-free photo courtesy Mikhail Kanevskiy; University of Alaska Fairbanks, Institute of Northern Engineering; 8/13/2011. (High resolution image)
Researchers from the U.S. Geological Survey and key academic partners have quantified how rapidly ancient permafrost decomposes upon thawing and how much carbon dioxide is produced in the process.
Huge stores of organic carbon in permafrost soils — frozen for hundreds to tens of thousands of years across high northern latitudes worldwide — are currently isolated from the modern day carbon cycle. However, if thawed by changing climate conditions, wildfire, or other disturbances, this massive carbon reservoir could decompose and be emitted as the greenhouse gases carbon dioxide and methane, or be carried as dissolved organic carbon to streams and rivers.
"Many scientists worldwide are now investigating the complicated potential end results of thawing permafrost," said Rob Striegl, USGS scientist and study co-author. "There are critical questions to consider, such as: How much of the stored permafrost carbon might thaw in a future climate? Where will it go? And, what are the consequences for our climate and our aquatic ecosystems?"
At a newly excavated tunnel operated by the U.S. Army Corps of Engineers near Fairbanks, Alaska, a research team from USGS, the University of Colorado Boulder, and Florida State University set out to determine how rapidly the dissolved organic carbon from ancient (about 35,000 years old) “yedoma” soils decomposes upon soil thaw and how much carbon dioxide is produced.
Yedoma is a distinct type of permafrost soil found across Alaska and Siberia that accounts for a significant portion of the permafrost soil carbon pool. These soils were deposited as wind-blown silts in the late Pleistocene age and froze soon after they were formed.
"It had previously been assumed that permafrost soil carbon this old was already degraded and not susceptible to rapid decomposition upon thaw," said Kim Wickland, the USGS scientist who led the team.
The researchers found that more than half of the dissolved organic carbon in yedoma permafrost was decomposed within one week after thawing. About 50% of that carbon was converted to carbon dioxide, while the rest likely became microbial biomass.Map of the northern circumpolar permafrost zone, highlighting the extent of the yedoma permafrost region (indicated in yellow and red). Map image and copyright permission courtesy of Macmillan Publishers Ltd, from NATURE, Schuur et al., 2015, Climate change and the permafrost carbon feedback, doi:10.1038/nature14338, copyright 2015. (High resolution image)
"What this study adds is that we show what makes permafrost so biodegradable," said Travis Drake, the lead author of the research. "Immediately upon thaw, microbes start using the carbon and then it is sent back into the atmosphere." Drake was both a USGS employee and a master’s degree student at the University of Colorado during the investigation.
The researchers attribute this rapid decomposition to high concentrations of low molecular weight organic acids in the dissolved organic carbon, which are known to be easily degradable and are not usually present at high concentrations in other soils.
These rates are among the fastest permafrost decomposition rates that have been documented. It is the first study to link rapid microbial consumption of ancient permafrost soil-derived dissolved organic carbon to the production of carbon dioxide.
An important implication of the study for aquatic ecosystems is that dissolved organic carbon released by thawing yedoma permafrost will be quickly converted to carbon dioxide and emitted to the atmosphere from soils or small streams before it can be transported to major rivers or coastal regions.
This research was recently published in the Proceedings of the National Academy of Sciences. The National Science Foundation’s Division of Polar Programs provided essential support for the investigation.
Working throughout the Mississippi River basin, USGS scientists and collaborators from the University of Texas at Austin have established the river’s own potential to decrease its load of nitrate and identified how certain basic river management practices could increase that potential.
"Increasing nitrogen concentrations, mostly due to the runoff of agricultural fertilizers, in the world's major rivers have led to over-fertilization of waters downstream, diminishing their commercial and recreational values,” said William Werkheiser, USGS associate director for water. “Understanding the natural potential of rivers themselves to remove nitrogen from the water, and boosting that potential, is a promising avenue to help mitigate the problem."
Beneath all streams and rivers is a shallow layer of sediment that is permeated by water exchange across the sediment surface. This thin region in the sediment beneath and to the side of the stream is referred to by scientists as the "hyporheic" zone, from Greek words meaning "under the flow."
"We’ve found in previous studies,” said Jesus Gomez-Velez, lead author of the study, “that the flow of stream water through this thin zone of sediment enhances chemical reactions by microbes that perform denitrification, a reaction that removes nitrogen from the aquatic system by converting it to nitrogen gas.” A USGS post-doctoral scientist at the time of the study, Gomez-Velez is now an assistant professor at the New Mexico Institute of Mining and Technology.
The research team determined that, throughout the Mississippi River network, vertical hyporheic exchange (with sediments directly beneath streams and rivers) has denitrification potential that far exceeds lateral hyporheic exchange with bank sediments.
"Rivers with more vertical exchange are more efficient at denitrification, as long as the contact time with sediment is matched with a reaction time of several hours," observed co-author Jud Harvey, the USGS team leader for the study.
The study findings suggest that managing rivers to help avoid the sealing of streambeds with fine sediments, which decreases hyporheic flow, would help exploit the valuable natural capability of rivers to improve their own water quality. Other river management and restoration practices that protect permeable river bedforms could also boost efficiency, such as reducing fine sediment runoff to rivers.
However, typical river channel restoration strategies that realign channels to increase meandering would not be as effective, because a comparatively small amount of water and river nitrate are processed through river banks compared with river beds. Although not yet tested in the model, allowing natural flooding over river banks onto floodplains may also be an effective means of processing large amounts of river water to remove nitrogen before it reaches sensitive coastal waters.
Conducted by USGS and partners from the New Mexico Institute of Mining and Technology and the University of Texas at Austin, the research investigation was recently published in the journal Nature Geoscience.The river corridor includes surface and subsurface sediments beneath and outside the wetted channel. Greater interaction between river water and sediment enhances important chemical reactions, such as denitrification, that improve downstream water quality. (high resolution image) Stream and river water make many excursions through hyporheic flow paths. The metrics in the diagram key denote the number of excursions that water makes through hyporheic flow paths per kilometer of river distance. Vertical exchange though streambed hyporheic flow paths is much more efficient compared with exchange through lateral (stream bank) hyporheic flow paths. Also, hyporheic exchange is less efficient in the Upper Mississippi River sub-basin compared with the Missouri or Ohio sub-basins. The primary reasons for different hyporheic flow efficiencies are differences in river basin slope and sediment textures that permit greater hyporheic flow in some areas compared to others. (high resolution image)
Eatontown, N.J. -- When it comes to destruction, disasters like Superstorm Sandy don’t discriminate: historic structures and environmentally sensitive areas that lie in the path of a storm are in just as much peril as less significant sites.
But when a historic structure or ecologically fragile area is damaged in a disaster, particular care must be taken to ensure that any repair or remediation that must take place is done in accordance with historic and environmental regulations.Language English
Restoration Handbook for Sagebrush Steppe Ecosystems, Part 1 - Understanding and Applying Restoration
Mountain big sagebrush - or Artemisia tridentata ssp. vaseyana - is a sub-species of big sagebrush that is found in primarily at higher elevation and colder, drier sites between the Rocky Mountains and the Cascades and Sierra Nevada. (High resolution image)
CORVALLIS, Ore. — Heightened interest in advancing sage-grouse conservation has increased the importance of sagebrush-steppe restoration to recover or create wildlife habitat conditions that meet the species’ needs. Today, the U.S. Geological Survey published part one of a three-part handbook addressing restoration of sagebrush ecosystems from the landscape to the site level.
"Land managers face many challenges in restoring sagebrush-steppe landscapes to meet multiple management objectives," said David Pyke, USGS ecologist and lead author of the new USGS Circular. "Many wildlife species require multiple types of habitat spread over many scales – landscape to local site level. Managers are challenged to know where, when and how to implement restoration projects so they are effective across all these scales."
The new handbook describes a sagebrush-steppe habitat restoration framework that incorporates landscape ecology principles and information on resistance of sagebrush-steppe to invasive plants and resilience to disturbance. This section of the handbook introduces habitat managers and restoration practitioners to basic concepts about sagebrush ecosystems, landscape ecology and restoration ecology, with emphasis on greater sage-grouse habitats.
Six specific concepts covered are:
- similarities and differences among sagebrush plant communities,
- plant community resilience to disturbance and resistance to invasive plants based on soil temperature and moisture regimes,
- soils and the ecology critical for plant species used for restoration,
- changes that can be made to current management practices or re-vegetation efforts in support of general restoration actions,
- landscape restoration with an emphasis on restoration to benefit sage-grouse and
- monitoring effectiveness of restoration actions in support of adaptive management.
"Restoration of an ecosystem is a daunting task that appears insurmountable at first," said Pyke. "But as with any large undertaking, the key is breaking down the process into the essential components to successfully meet objectives. Within the sagebrush steppe ecosystem, restoration is likely to be most successful with a better understanding of how to prioritize landscapes for effective restoration and to apply principles of ecosystem resilience and resistance in restoration decisions."
Pyke noted that the blending of ecosystem realities – such as soil, temperature and moisture – with species-specific needs provides an ecologically based framework for strategically focusing restoration measures to support species of conservation concern over the short and long term.
Part one of the handbook sets the stage for two decision support tools. Part two of the handbook will provide restoration guidance at a landscape level, and part three, restoration guidance at the site level.
The handbook was funded by the U.S. Joint Fire Science Program and National Interagency Fire Center, Bureau of Land Management, Great Northern Landscape Conservation, USGS, and Western Association of Fish and Wildlife Agencies with authors from the USGS, U.S. Forest Service, Bureau of Land Management, Oregon State University, Utah State University and Brigham Young University.
Greater sage-grouse occur in parts of 11 U.S. states and 2 Canadian provinces in western North America. Implementation of effective management actions for the benefit of sage-grouse continues to be a focus of Department of the Interior agencies following the decision by the U.S. Fish and Wildlife Service that the species is not warranted for listing under the Endangered Species Act.
COLUMBIA, S.C. – Two disaster recovery centers are open in Georgetown County to help South Carolina flood survivors. The centers - one in Andrews and the other in Georgetown - are open 8 a.m. to 7 p.m. seven days a week until further notice.
The new centers are located at Potato Bed Ferry Community Center, 531 Big Dam Swamp Drive in Andrews and Beck Recreation Center at 2030 West Church St. in Georgetown.
They replace the center that closed on Friday at the Walmart parking lot at 1295 Frazier St. in Georgetown.Language English
COLUMBIA, S.C. – The disaster recovery center in Gadsden has new hours on Sundays from 2 p.m. to 7 p.m.
The center’s Monday-to-Saturday hours remain 8 a.m. to 7 p.m. until further notice.
Representatives from the South Carolina Emergency Management Division, the Federal Emergency Management Agency, the U.S. Small Business Administration and other public and private agencies are at the center to explain disaster assistance programs and help survivors with applications for aid.
The disaster recovery center is located at the following address:Language English
SACRAMENTO, Calif. – The California Governor’s Office of Emergency Services will conduct applicant briefings in Lakeport Monday and in San Andreas Wednesday to inform representatives of local government agencies and certain private nonprofits how to file requests for assistance with losses caused by the Butte and Valley fires in Lake and Calaveras counties.Language English
COLUMBIA, S.C. – As South Carolinians rebuild and repair after the recent historic floods, the Federal Emergency Management Agency and local home improvement stores have teamed up to provide free information, tips and literature on making homes stronger and safer.Language English
ATLANTA -- Ten years ago October 24, Hurricane Wilma slammed ashore near Naples, Fla., as a Category 3 storm with a 50-mile-wide eye. Wilma was the most intense hurricane on record in the Atlantic Basin, with wind speeds reaching 175 mph over the Gulf of Mexico.Language English
During the historic October 2015 floods in South Carolina, 17 U.S. Geological Survey streamgages recorded the highest peak streamflow and/or river height (or stage) since those streamgages were installed. An additional 15 USGS streamgages recorded peaks in the top 5 for their periods of record.
One of these streamgages, located on the Black River at Kingstree, South Carolina, recorded its largest peak in the 87 years it has existed. The streamgage showed that the Black River reached a peak streamflow of 83,700 cubic feet per second and a stage of 22.65 feet. The previous maximum on the Black River occurred on June 14, 1973. Additional annual peak stage data collected by the National Weather Service at the gauge prior to USGS operation indicates this is likely the highest flood since 1893.
"This was absolutely an historic flood for South Carolina," said John Shelton, the USGS hydrologist who oversaw the agency’s field response and gauging operations in South Carolina. "Throughout the event we continued to monitor our network of about 170 real-time streamgages, and we sent dozens of teams out in the field to verify what we were seeing. Fortunately, we have quite a few long-standing streamgages in South Carolina, so we can put these floods into historical context."
One of the longest-running streamgages in South Carolina is the one on the Congaree River in Columbia, with annual records back to 1892 and even flood information for 1852. That means that there are 123 years of record to place the October 2015 floods into perspective.
The USGS streamgage on the Congaree River at Columbia peaked at 185,000 cubic feet per second at a peak stage of 31.8 feet on October 4, 2015. When compared to the historical flood record, this peak ranks eighth out of 123 years of record with the peak of record being 364,000 cubic feet per second at a peak stage of 39.8 feet on August 27, 1908.
However, the October 2015 flood on the Congaree River is the highest since April 8, 1936, when the river peaked at 231,000 cubic feet per second at a peak stage of 33.3 ft.
For comparison, an Olympic-sized swimming pool contains 88,000 cubic feet, so the October 4, 2015, peak on the Congaree River at Columbia would fill a little over two Olympic-sized swimming pools every second.
Throughout the entire flood, the USGS deployed nearly 100 people who collected almost 250 distinct streamflow measurements in South Carolina, North Carolina, and Georgia; deployed and recovered storm-tide sensors and Rapid-Deployment Gauges; and flagged and determined the elevation of close to 600 high-water marks in support of response and recovery missions for FEMA. The effort, led by the USGS South Atlantic Water Science Center, which has offices in South Carolina, North Carolina, and Georgia, was supported by teams from other USGS offices in Alabama, Florida, Mississippi and Pennsylvania.
A total of 8 streamgages were destroyed or damaged during the floods in South Carolina, with five replaced with Rapid-Deployment Gauges within hours of the gauge outage.
In South Carolina, the teams made about 140 streamflow measurements at about 86 real-time streamgages to verify or update existing information on streamflow at that site. This information, along with a comparison of historic peak flows or stages and a chronology of major flood events in South Carolina since 1893, is available in a new USGS report entitled "Preliminary Peak Stage and Streamflow Data at Selected USGS Streamgaging Stations for the South Carolina Flood of October 2015."
Installation of seven Manufactured Housing Units underway
Who: California Governor’s Office of Emergency Services (Cal OES)
Federal Emergency Management Agency (FEMA)
What: Media members will have an opportunity to tour one of the manufactured housing units Cal OES and FEMA are installing in Calaveras and Lake counties to provide temporary housing for eligible survivors of the Butte and Valley wildfires.Language English
COLUMBIA, S.C. – A disaster recovery center is open in St. Matthews to help South Carolina flood survivors. This Calhoun County center is open 8 a.m. to 7 p.m. seven days a week until further notice.
Representatives from the South Carolina Emergency Management Division, Federal Emergency Management Agency, U.S. Small Business Administration and other agencies are at the center to answer questions about disaster assistance and low-interest loans. They can also help survivors apply for aid.Language English
EATONTOWN, N.J. -- The devastation caused by Hurricane Sandy left survivors and businesses in New Jersey with large-scale recovery needs. In the three years since, the state’s private sector has made significant contributions to strengthen recovery efforts.
Immediately after Sandy struck, Private Sector specialists with FEMA’s External Affairs division deployed to New Jersey to work with chambers of commerce, industry associations, individual companies, colleges and universities, the medical industry and other organizations.Language English
NEW YORK – FEMA and the U.S. Small Business Administration have disbursed nearly $16.9 billion for New York’s recovery since Hurricane Sandy made landfall on the East Coast three years ago. This amount includes more than $1 billion paid directly to survivors for housing and other essential needs through the Individuals and Households Program which ended April 30, 2014.Language English
A new approach by U.S. Geological Survey scientists to modeling water temperatures resulted in more realistic predictions of how climate change will affect fish habitat by taking into account effects of cold groundwater sources.
The study, recently published in the journal Ecological Applications, showed that groundwater is highly influential but also highly variable among streams and will lead to a patchy distribution of suitable fish habitat under climate change. This new modeling approach used brook trout, but can be applied to other species that require coldwater streams for survival.
"One thing that has been missing from other models is the recognition that groundwater moderates the temperature of headwater streams," said Nathaniel Hitt, a fish biologist and study coauthor. "Our paper helps to bring the effects of groundwater into climate change forecasts for fish habitat."
Climate change models predict that summer air temperatures will increase between 2.7 and 9 degrees Fahrenheit in the eastern United States over the next 50 to 100 years. Such increases in air temperatures will increase water temperatures of streams and rivers and pose a significant threat to fish like brook trout that have low resistance to warming water temperatures.
Brook trout are an important cultural and recreational species with specific restoration outcomes identified in the new Chesapeake Bay Agreement.
However, how these global and regional predictions regarding a changing climate translate to water temperatures in specific streams or stream reaches, a process called “downscaling”, remains an important and challenging question for scientists and natural resource managers.
Previous efforts to downscale global and regional estimates of air temperature change down to water temperatures in individual streams and river networks have relied on the assumption that the exchange of heat between the water and the surrounding air is the primary driver of water temperature within an individual section of a stream. However, the exchange of heat between cold groundwater and warmer surface water can also be very important, especially in headwater streams where the volume of water is relatively small.
"Our models help improve the spatial resolution of climate change forecasts in headwater streams," said Craig Snyder, a USGS research ecologist and lead author of the study. "This work will assist conservation and restoration efforts by connecting climate change models to places that matter for stream fishes."
The study is available online: Snyder, C.D., N.P. Hitt, and J.A. Young. 2015. Accounting for groundwater in stream fish thermal habitat responses to climate change. Ecological Applications 25:1397-1419.
SAIPAN, CNMI – Typhoon Soudelor survivors on Saipan who need to get documents to the Federal Emergency Management Agency have several places where they can do so free of charge.
When the joint CNMI/FEMA Disaster Recovery Center in Susupe closed earlier this month, the Commonwealth of the Northern Mariana Islands began arranging locations that would provide this service to survivors. That list currently stands at four:
Saipan Mayor’s OfficeLanguage Undefined
SAIPAN, CNMI – FEMA Mitigation Outreach specialists are updating their schedule.
They are currently at Do-It-Best Hardware in Chalan Kiya, meeting with customers and providing booklets and pamphlets on how to build back stronger to be safer in the next storm. They are in the store from 10 a.m.-4 p.m. weekdays, and will continue there through Friday, Oct. 23.Language Undefined
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Washington.
Assistance for the State, Tribal and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. -- The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Washington and ordered federal aid to supplement state, tribal and local recovery efforts in the area affected by wildfires and mudslides during the period of August 9 to September 10, 2015.Language English
SACRAMENTO, Calif. – The Federal Emergency Management Agency and Cal OES are altering the schedules of Disaster Recovery Centers (DRCs) in Calaveras and Lake counties, with two Mobile Disaster Recovery Centers closing permanently.
Starting this weekend the DRC hours of operation will be:
Monday – Friday: 8 a.m. – 6 p.m.
Saturday: 9 a.m. – 4 p.m.Language English