Mount McKinley Elevation Survey Results Coming Soon plus 1 more |
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Mount McKinley Elevation Survey Results Coming Soon Posted: 23 Jul 2015 06:30 AM PDT
Summary: A team of four climbers has recently returned from the highest point in North America with new survey data to determine a more precise summit height of Mount McKinley. It is anticipated the new elevation finding will be announced in late August
Climbers return from the top of Mount McKinley to begin data analysisContact Information: Mark Newell, USGS ( Phone: 573-308-3850 ); Sue Mitchell, UAF GI ( Phone: 907-474-5823 ); Vicki Childers, NOAA/NGS ( Phone: 301-713-3211 x161 ); A team of four climbers has recently returned from the highest point in North America with new survey data to determine a more precise summit height of Mount McKinley. It is anticipated the new elevation finding will be announced in late August. The ability to establish a much more accurate height has grown with advances in surveying technologies since 1953 when the last official survey of Mount McKinley was recorded. The new elevation will eventually replace the formerly accepted elevation of 20,320 feet. ”Determining an updated elevation for the summit of Mount McKinley presents extraordinary challenges,” said Suzette Kimball, acting director of the USGS. “The USGS and its partners are using the best available modern GPS survey equipment and techniques to ensure the new elevation will be determined with a high level of accuracy and confidence.” Unique circumstances and variables such as the depth of the snow pack and establishing the appropriate surface that coincides with mean sea level must be taken into account before the new Mount McKinley elevation can be determined. In 2013, an elevation was calculated for Mount McKinley using a technology known as Interferometric Synthetic Aperture Radar (ifsar). The 2013 elevation was slightly lower than the summit’s 20,320 foot height. Ifsar is an extremely effective tool for collecting map data in challenging areas such as Alaska, but it does not provide precise spot or point elevations. This new survey used GPS instruments that were placed directly on the summit to measure a specific point on the surface, thus giving a more defined spot elevation. The USGS, along with NOAA’s National Geodetic Survey (NGS), and the University of Alaska Fairbanks (UAF), are the primary partners supporting the survey of McKinley’s summit. The survey party included three GPS experts and mountaineers from CompassData (a subcontractor for Dewberry), and a scientist/climber from UAF’s Geophysical Institute. Now that the data collection expedition is completed, the NGS, UAF, USGS and CompassData are in the process of analyzing the data. "CompassData was honored to help the USGS and NOAA on this nationally important project,” said Blaine Horner, a member of the climbing team. “Our experience surveying around the world put us in a unique position to perform this work." The team began their ascent, with the needed scientific instruments in tow, on June 16. With diligent work and mostly favorable weather, the team safely returned to their starting point ahead of schedule. "We had nearly perfect weather on the mountain,” said Tom Heinrichs, Director of the UAF Geographic Information Network of Alaska and part of the climbing team. “The logistics on the mountain all went well. The summit survey was successful and our preliminary look at the data indicates we will get a good solution for the summit elevation." Mount McKinley is part of Denali National Park. The Park hosts more than 530,000 visitors each year, with about 1,200 who attempt to climb Mount McKinley. In a typical year, about half of those who begin a McKinley climb reach the summit. The six million acre park will celebrate its 100th anniversary in 2017. The mountain was first summited in 1913.
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Climate Change Reduces Coral Reefs' Ability to Protect Coasts Posted: 22 Jul 2015 10:00 AM PDT
Summary: Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands
Contact Information: Mariska van Gelderen, Deltares ( Phone: +31 (0)6 13 67 13 70 ); Leslie Gordon, USGS ( Phone: 650-329-4006 ); Nanci Bompey, AGU ( Phone: 202-777-7524 );
SANTA CRUZ, Calif. — Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands. A new paper by researchers from the Dutch independent institute for applied research Deltares and the U.S. Geological Survey gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards. About 30 million people are dependent on the protection by coral reefs as they live on low-lying coral islands and atolls. At present, some of these islands experience flooding due to wave events a few times per decade. It is expected that this rate of flooding will increase due to sea level rise and coral reef decay, as the remaining dead corals are generally smoother in structure, and do less to dissipate wave energy. Loss of coral cover not only causes increased shoreline erosion but also affects the sparse drinking water resources on these islands, which may eventually make these islands uninhabitable. In order to prevent or mitigate these impacts, coastal managers need know to what extent their reef system may lose its protective function so that they can take action. The new study gives guidance on a local reef’s sensitivity to change. The new research has been accepted for publication in “Geophysical Research Letters,” a journal of the American Geophysical Union. To gain insight into effects of changing conditions on coral reefs, the study authors used Xbeach (an open-source wave model). The computer model was first validated using field measurements obtained on the Kwajalein Atoll in the Marshall Islands in the Pacific Ocean, and was then used to investigate what the effects on water levels, waves, and wave-driven runup would be if certain reef properties change. Reef roughness, steepness, width and the total water level on the reef platform are all important factors for coastal managers to consider when planning mitigating measures. The results suggest that coasts fronted by relatively narrow reefs with steep faces and deeper, smoother reef flats are expected to experience the highest wave runup and thus potential for island flooding. Wave runup increases for higher water levels (that are expected with sea level rise), higher waves, and lower bed roughness (as coral degrades and becomes smoother), which are all expected effects of climate change. Rising sea levels and climate change will have a significant negative impact on the ability of coral reefs to mitigate the effects of coastal hazards in the future. The research paper, “The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines,” is published as an open-access paper and available online. Quataert, E., C. Storlazzi, A. van Rooijen, O. Cheriton, and A. van Dongeren (2015), The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines, Geophysical Research Letters, 42, doi:10.1002/2015GL064861 Deltares is an independent institute for applied research in the field of water and subsurface. Visit http://www.deltares.nl and follow us on Twitter @deltares or LinkedIn. |
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