{"id":213,"date":"2012-08-18T17:17:45","date_gmt":"2012-08-18T21:17:45","guid":{"rendered":"http:\/\/noaacoastsurvey.wordpress.com\/?p=213"},"modified":"2022-03-18T16:55:16","modified_gmt":"2022-03-18T16:55:16","slug":"fairweather-collects-hydro-data-on-alaskas-north-slope","status":"publish","type":"post","link":"https:\/\/nauticalcharts.noaa.gov\/updates\/fairweather-collects-hydro-data-on-alaskas-north-slope\/","title":{"rendered":"NOAA Ship Fairweather crew takes in Arctic beauty as they collect hydro data off Alaska’s North Slope"},"content":{"rendered":"

by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220)<\/em>
\n1200 hours, August 17, 2012: <\/strong>70\u00b013.7\u2019N\u00a0 144\u00b049.6\u2019W, approximately 250 nautical miles along the coast SSE of Barrow, AK<\/em>
\nThe water turned a silty gray-green early afternoon yesterday, Thursday, August 16. The Fairweather <\/em>was transiting through areas with depths under our keel of between 8 and 20 meters \u2013 a somewhat caution-inducing sight for a vessel of our size. But the ice has opened up and we have made it east of Barrow. We are currently the furthest east along the North Slope of any NOAA or U.S. Coast and Geodetic Survey hydrographic ship, as previous surveys were last conducted by field parties with much smaller boats, in the 1950s and 1960s. As the crow flies, we are currently 90 miles or so west of the Canadian border and our turn-around point. However, we are of course not transiting in a straight line but in the zigzag\/argyle pattern, so have a bit more sea floor to cover.
\n
\nFor a normal hydrographic survey, we use the Fairweather<\/em> and her launches to drive over an area slowly and methodically with set parallel line spacing. With the multibeam echo-sounders, we are able to record data for a swath of between five and seven times the depth in which we are surveying. The survey lines are spaced to have a minimum of 25% overlap and thus comprehensive coverage of an area as well as moderate redundancy to ensure accuracy of the data collected.
\nAs this Arctic trip is a \u201creconnaissance\u201d survey<\/a>, we are using the argyle pattern to cover as much area as possible while still ensuring quality of data via some overlap of tracklines. The image below provides a good visual. This pattern allows us to evaluate the data on the charts though varying depths. The blue lines represent one year (out and back) and the red the next year (out and back again). By crossing over previously surveyed lines \u2013 both within one season\u2019s trip to the border and back, and potentially from one year to the next \u2013 we can both verify the data from the prior acquisition and help determine where there might be relatively rapid changes in the bottom characteristics (due to strong currents and a soft bottom, for instance).<\/p>\n

\"argyle<\/a><\/p>\n

Our current trackline has been modified yet again. Due to the ice, instead of surveying an area between 5 nautical miles (nm) and 60 nm out from shore, we have compressed our accordion to range between 1.5 nm and 30 nm out. From our observations, looking at aerial images of the sea ice, and listening in on radio traffic between the limited vessels transiting the area, it is looking promising that we will make it to Demarkation Point, on the Canadian border.<\/p>\n

*\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 *\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 *<\/p>\n

We weren\u2019t feeling so optimistic a week ago.
\nA combination of heavy fog and ice fields unexpectedly far south made data acquisition \u2013 bottom samples and CTD casts (measuring conductivity, temperature, and depth) \u2013 impossible at our scientists\u2019 scheduled sample sites, and required deviation from the intended survey route. However, our plans on the Fairweather <\/em>continued to adapt to the developing conditions, and not only were we able to satisfy our scientists research needs, but we also were able to experience some pretty cool Arctic phenomena. Oh, and squeeze in a little extra surveying just outside of the town of Barrow \u2013 in order to provide \u201cground truth\u201d data to support a study on the feasibility of satellite-derived bathymetry to update nautical charts.
\nThis past week, however, is best told in pictures taken this Arctic trip by NOAA Ship Fairweather <\/em>crewmembers.
\n

\"view<\/a>
Our first sight of ice on the Fairweather, August 10, 2012 (71\u00b014\u2019N 160\u00b056\u2019W), through the eye of the ship\u2019s alidade. Photo by Tim Smith, LT\/NOAA<\/figcaption><\/figure>
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While waiting for the ice and fog to clear sufficiently for the Fairweather to continue its mission, the crew all took part in a \u201creconnaissance\u201d by small boat along the ice edge. Photo by Grant Froelich, NOAA<\/figcaption><\/figure>
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Photo by Brian Glunz, NOAA<\/figcaption><\/figure>
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Photo by Scott Broo, ENS\/NOAA<\/figcaption><\/figure>
\n
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We all felt a little bad for the folks who had to wait until the end of the day to go explore the ice in the launch. Until they came back with pictures of walruses.<\/figcaption><\/figure>
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Photo by Tim Smith, LT\/NOAA<\/figcaption><\/figure>
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A couple of days later, there was a hurried call on the radio from the bridge to survey, requesting that they pull in their MVP (moving vessel sound speed profiler) \u201cfish\u201d being towed behind the Fairweather \u2013 we were approaching a large field of ice and needed to be prepared to maneuver. However, the ice never got any closer. It turned out to be an example of Fata Morgana \u2013 an Arctic mirage, caused by the refraction of light rays due to the cold and dense polar air. Photo by Shauna Glasser, NOAA<\/figcaption><\/figure>
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Viewed through binoculars, our very own \u201cghost ship.\u201d This ship was actually 23 miles away at the time \u2013 over the visible horizon. Photo by Scott Broo, ENS\/NOAA<\/figcaption><\/figure>
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Another phantom vessel \u2013 this one only six miles away, but appearing much closer. Photo by Casey Marwine, ENS\/NOAA<\/figcaption><\/figure>
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A little bit of everything \u2013 ice, midnight sunsets, and some Arctic special effects. Photo by Scott Broo, ENS\/NOAA<\/figcaption><\/figure><\/p>\n","protected":false},"excerpt":{"rendered":"

by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220) 1200 hours, August 17, 2012: 70\u00b013.7\u2019N\u00a0 144\u00b049.6\u2019W, approximately 250 nautical miles along the coast SSE of Barrow, AK The water turned a silty gray-green early afternoon yesterday, Thursday, August 16. The Fairweather was transiting through areas with depths under our keel of between 8 … <\/p>\n

Continue reading “NOAA Ship Fairweather crew takes in Arctic beauty as they collect hydro data off Alaska’s North Slope”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[39,40,7],"tags":[315,316],"class_list":["post-213","post","type-post","status-publish","format-standard","hentry","category-arctic","category-fairweather","category-hydrographic-surveys","tag-north-slope","tag-reconnaissance-survey"],"_links":{"self":[{"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/posts\/213","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/comments?post=213"}],"version-history":[{"count":1,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/posts\/213\/revisions"}],"predecessor-version":[{"id":182465,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/posts\/213\/revisions\/182465"}],"wp:attachment":[{"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/media?parent=213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/categories?post=213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nauticalcharts.noaa.gov\/updates\/wp-json\/wp\/v2\/tags?post=213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}