New Maps for Colorado and Minnesota plus 1 more

[USGS Newsroom <oc_web@xxxxxxxx>]

Title: USGS Newsroom

New Maps for Colorado and Minnesota plus 1 more

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New Maps for Colorado and Minnesota

Posted: 12 Sep 2013 06:00 AM PDT

Newly designed US Topo maps covering Colorado and Minnesota are now available online for free download

In keeping with rapid demand, the USGS has posted new US Topo quadrangles covering Colorado (1,794 maps) and Minnesota (1,689). These new quads replace the first edition US Topo maps for those states. The replaced maps will be added to the USGS Historical Topographic Map Collection and are also available for free download from The National Map and the USGS Map Locator & Downloader website.

The new design for US Topo maps improves readability of maps for online and printed use, while retaining the look and feel of the traditional USGS topo map. Also, map symbols are now easier to read over the digital aerial photograph layer whether the imagery is turned on or off. 

 Other re-design enhancements and new features:

• New shaded relief layer for enhanced view of the terrain
• Military installation boundaries, post offices and cemeteries
• New road classification
• A slight screening (transparency) has been applied to some features to enhance visibility of multiple competing layers
• New PDF legend attachment
• Metadata formatted to support multiple browsers

In addition, the new Colorado US Topo quads include recreational trails in National Forests, provided by the U.S. Forest Service. Although this first test of trails was successful, the Forest Service does not yet have comparable data in other states, and schedules for adding trails in all National Forests have not been set.

"We are excited to about these two updates that are part of our continual effort to improve US Topo maps for our users," said Vicki Lukas, USGS Chief of Partner and User Engagement. "First, the new design makes US Topo maps even easier to use, and the new Colorado maps include Forest Service trails as a new feature."

US Topo maps are updated every three years. The initial round of the 48 conterminous state coverage was completed last September. Hawaii and Puerto Rico maps are being completed this year. New US Topo maps for Alaska have started, but will take several years to complete.

US Topo maps are created from geographic datasets in The National Map, and deliver visible content such as high-resolution aerial photography, which was not available on older paper-based topographic maps. The new US Topo maps provide modern technical advantages that support wider and faster public distribution and on-screen geographic analysis tools for users.

The new digital electronic topographic maps are delivered in GeoPDF image software format and may be viewed using Adobe Reader, available as a no-cost download.

For more information, go to: http://nationalmap.gov/ustopo/

Figure showing proposed US Topo production schedule. States that were updated in 2012 are in yellow; states that have, or will be updated in 2013 are colored red; and states are scheduled to be updated in 2014 are in blue. (High resolution image)

Unprecedented Rate and Scale of Ocean Acidification Found in the Arctic

Posted: 11 Sep 2013 02:30 PM PDT

ST. PETERSBURG, Fla. — Acidification of the Arctic Ocean is occurring faster than projected according to new findings published in the journal PLOS ONE.  The increase in rate is being blamed on rapidly melting sea ice, a process that may have important consequences for health of the Arctic ecosystem.

Ocean acidification is the process by which pH levels of seawater decrease due to greater amounts of carbon dioxide being absorbed by the oceans from the atmosphere.  Currently oceans absorb about one-fourth of the greenhouse gas.  Lower pH levels make water more acidic and lab studies have shown that more acidic water decrease calcification rates in many calcifying organisms, reducing their ability to build shells or skeletons.  These changes, in species ranging from corals to shrimp, have the potential to impact species up and down the food web.

The team of federal and university researchers found that the decline of sea ice in the Arctic summer has important consequences for the surface layer of the Arctic Ocean.  As sea ice cover recedes to record lows, as it did late in the summer of 2012, the seawater beneath is exposed to carbon dioxide, which is the main driver of ocean acidification.

In addition, the freshwater melted from sea ice dilutes the seawater, lowering pH levels and reducing the concentrations of calcium and carbonate, which are the constituents, or building blocks, of the mineral aragonite. Aragonite and other carbonate minerals make up the hard part of many marine micro-organisms’ skeletons and shells. The lowering of calcium and carbonate concentrations may impact the growth of organisms that many species rely on for food. 

The new research shows that acidification in surface waters of the Arctic Ocean is rapidly expanding into areas that were previously isolated from contact with the atmosphere due to the former widespread ice cover.

"A remarkable 20 percent of the Canadian Basin has become more corrosive to carbonate minerals in an unprecedented short period of time.  Nowhere on Earth have we documented such large scale, rapid ocean acidification" according to lead researcher and ocean acidification project chief, U.S. Geological Survey oceanographer Lisa Robbins.

Globally, Earth's ocean surface is becoming acidified due to absorption of man-made carbon dioxide. Ocean acidification models show that with increasing atmospheric carbon dioxide, the Arctic Ocean will have crucially low concentrations of dissolved carbonate minerals, such as aragonite, in the next decade.

"In the Arctic, where multi-year sea ice has been receding, we see that the dilution of seawater with melted sea ice adds fuel to the fire of ocean acidification" according to co-author, and co-project chief, Jonathan Wynn, a geologist from the University of the South Florida. "Not only is the ice cover removed leaving the surface water exposed to man-made carbon dioxide, the surface layer of frigid waters is now fresher, and this means less calcium and carbonate ions are available for organisms."

Researchers were able to investigate seawater chemistry at high spatial resolution during three years of research cruises in the Arctic, alongside joint U.S.-Canada research efforts aimed at mapping the seafloor as part of the U.S. Extended Continental Shelf program.  In addition to the NOAA supported ECS ship time, the ocean acidification researchers were funded by the USGS, National Science Foundation, and National Oceanic and Atmospheric Administration.

Compared to other oceans, the Arctic Ocean has been rather lightly sampled. "It's a beautiful but challenging place to work," said Robert Byrne, a USF marine chemist. Using new automated instruments, the scientists were able to make 34,000 water-chemistry measurements from the U.S. Coast Guard icebreaker. "This unusually large data set, in combination with earlier studies, not only documents remarkable changes in Arctic seawater chemistry but also provides a much-needed baseline against which future measurements can be compared." Byrne credits scientists and engineers at the USF college of Marine Science with developing much of the new technology.

Information on the most recent Arctic research cruise is available on online, and you can follow the research on Twitter @USGS Arctic.