New Model Improves Predictions for How Climate Change Will Affect Fish Habitat plus 1 more

[USGS Newsroom <noreply+feedproxy@xxxxxxxxxx>]

Title: USGS Newsroom

New Model Improves Predictions for How Climate Change Will Affect Fish Habitat plus 1 more

---

New Model Improves Predictions for How Climate Change Will Affect Fish Habitat

Posted: 21 Oct 2015 05:58 AM PDT

Summary: 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.

---

Contact Information:

Craig Snyder ( Phone: 304-724-4468 ); Nathaniel Hitt ( Phone: 304-724-4463 ); Hannah Hamilton ( Phone: 703-648-4356 );

---

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.

A Century of Induced Earthquakes in Oklahoma?

Posted: 20 Oct 2015 12:51 PM PDT

Summary: The rate of earthquakes has increased sharply since 2009 in the central and eastern United States, with growing evidence confirming that these earthquakes are primarily caused by human activity, namely the injection of wastewater in deep disposal wells

---

Contact Information:

Donyelle Davis ( Phone: 626-202-2393
 );

---

Cimmarron River bed operations in Cushing Oil Field, Oklahoma, Looking Southwest. Creek County, Oklahoma. December 2, 1915. Panorama in two parts. / USGS archive Photo. (High resolution image)

The rate of earthquakes has increased sharply since 2009 in the central and eastern United States, with growing evidence confirming that these earthquakes are primarily caused by human activity, namely the injection of wastewater in deep disposal wells.  A new study by the U.S Geological Survey released today presents evidence that, in addition to these recent earthquakes, most of the larger earthquakes in Oklahoma in the past century may likely have been induced by industrial activities.

This study explores the especially high rates of activity in Oklahoma, the background rate of natural earthquakes in the state and how much the earthquake rate has varied through the 20^th century.  

"In Oklahoma, seismicity rates since 2009 far surpass previously observed rates at any time during the 20th century," said Susan Hough, USGS seismologist and lead author of the study.  "Several lines of evidence further suggest that most of the significant earthquakes in Oklahoma during the 20th century may also have been induced by oil production activities. Deep injection of waste water, now recognized to potentially induce earthquakes, in fact began in the state in the 1930s."

The study uses archival reports at the Library of Congress and drill permit records showing the location of wells from the Oklahoma Corporation Commission to track how wastewater injection evolved over time, with an increase around 1950 due to a rise in secondary oil recovery in response to  increasing depletion of fields.

"Waste water injection has a strong correlation to the increase in earthquakes," said Morgan Page, USGS seismologist and co-author of the study. "The results further demonstrate that, while the rates seen in recent years are unprecedented, induced earthquakes are likely nothing new in Oklahoma."

Oil production in Oklahoma has been going on for over 100 years.  Some activities related to oil production, particularly disposal of wastewater in deep injection wells, are known to potentially cause earthquakes.  Prior to the 2011 magnitude 5.7 Prague, Oklahoma earthquake, the largest historical earthquake in the area was the 1952 magnitude 5.7 El Reno earthquake, which the study concludes was likely induced by activities related to oil production near Edmond, Oklahoma. 

The complete research paper, "A Century of Induced Earthquakes in Oklahoma?" by Susan E. Hough and Morgan Page was released online in the journal Bulletin of the Seismological Society of America.