Tag Archives: helicopter

How oceans interact with Greenland’s last floating glaciers

Testifying before the US Congress back in 2010, I refused to endorse the view that a first large calving at Petermann Gletscher in North Greenland was caused by global warming. When a second Manhattan-sized iceberg broke off in 2012, I was not so sure anymore and looked closely at all available data. There was not much, but what little I found suggested that ocean temperatures were steadily increasing. Could it be that warm waters 1000 feet below the surface could melt the glacier at all times of the year? Did this melting from below thin the glacier? Did these changes increase the speed at which it moves ice from land into the ocean? These were the questions that motivated a number of projects that began in earnest in 2015 aboard the Swedish icebreaker I/B Oden. Professional videos of this expeditions are at https://icyseas.org/2019/07/04/petermann-glacier-videos-science/

Scientists and technicians from the British Antarctic Survey drilled three holes through the floating section of Petermann Gletscher to access the ocean and ocean sediments below it. The ocean temperature and salinity profile confirmed both the warming trend observed in the fjord and ocean adjacent to the glacier, but more importantly, we placed ocean sensors below the glacier ice to measure temperature and salinity every hour for as long as the sensors, cables, and satellite data transmission would work. This has never been done around Greenland, so our data would be the first to report in real time on ocean properties below 100 to 300 m thick glacier ice at all times. What we saw when the data started to come in after 2 weeks, a month, and half a year stunned us, because (a) the ocean waters under the glacier changed by a very large amount every two weeks. Nobody has ever seen such regular and large changes in tempertures (and salinity) under a glacier bathed in total darkness at air temperatures of -40 degrees Celsius and Fahrenheit, but then our station went offline after 6 months and did not report any data to us via satellite.

Helicopter flight path on 27/28 August 2016 to reach Petermann Gletscher (PG) via southern (Fuel-S) and northern (Fuel-N) fuel stops in northern Inglefield and southern Washington Land, respectively. Background color is ocean bottom depth in meters.

Refurbished Petermann Glacier Ocean Weather station on 28. August 2016 with Greenland Air helicopter and British Antarctic radar station in the background.

The first work on the grant was to visit our station by helicopter in 2016 using two fuel caches that we placed the year prior from the Swedish icebreaker. At this point Petermann Gletscher and our projects attracted the attention of journalists of the Washington Post who had read some of the blog articles at this site. The two journalists accompanied us for a week and produced a beautiful visual report of our work that is posted at

https://www.washingtonpost.com/sf/business/2016/12/30/with-enough-evidence-even-skepticism-will-thaw/

A detailed news report on our science and new findings appeared on page-1 of the Washington Post on January 1, 2017 [Broader Impacts]. I briefly summarize the results and findings of our subsequent data analyses of all data from August of 2015 through October of 2017 [Intellectual Merit]:

1a. Ocean temperatures increase at all five depths below the 100-m thick floating ice shelf of the glacier. These warmer waters are also saltier which demonstrates their Atlantic origin.

1b. Surface sensors indicate short, but intense pulses of meltwater passing our ocean array at spring-neap tidal cycles.

2a. Melt rate data reveal that these pulses occur during reduced tidal amplitudes and follow peaks in glacier melting that exceeded 30 feet per year.

2b. Statistical analyses indicate that the melt waters originate from a location near where the glacier sits on bed rock and that the melt water then moves seaward towards the ocean.

3a. Ocean melting below the glacier varies from summer (strong) to winter (weak) rising from a winter mean of 6 feet per year to a maximum of 240 feet per year during the summer.

3b. The large summer melting is caused by the increased discharge of subglacial runoff into the ocean near the grounding line.

3c. The larger discharge strengthens ocean currents under the floating glacier that drive ocean heat toward the glacier’s ice base.

The work formed one basis for the dissertation of PhD student Peter Washam who published the items #2 and #3 in the Journal of Physical Oceanography and Journal of Glaciology, respectively. He helped to drill holes and install sensors for the project that we first described at #1 in Oceanography. These three peer-reviewed journal articles are all published by not-for-profit professional organizations and societies dedicated to higher learning and public outreach. Furthermore we placed three separate data sets (1 | 2 | 3) at the Arctic Data Center that is funded by the National Science Foundation. More will come as we continue to work on the hard-won data from below Petermann Gletscher.

Look down the 0.3 meter wide drill hole. Yellow kevlar rope supports cable and ocean sensors.

Post Scriptum:
A modified version of the above was submitted the US National Science Foundation as part of the final reporting on grant 1604076 (“Glacier-Ocean interactions at a Greenland ice shelf at tidal to interannual time scales”) that funded this work with $360,400 at the University of Delaware from August 2016 through July 2019.

Remote Air Strips in North Greenland

Where to land a plane in North Greenland? This remote wilderness has the last floating ice shelves in the northern hemisphere such as Petermann Gletscher. Two weeks ago Dr. Keith Nicholls of the British Antarctic Service (BAS) and I visited this glacier to fix both ice penetrating radars and ocean moorings that we had deployed in 2015 after drilling through more than 100 meters of glacier ice. The BAS radars measure how the ice thins and thickens during the year while my moorings measure ocean properties that may cause some of the melting. Keith and I are thinking how we can design an experiment that will reveal the physics of ocean-glacier interactions by applying what we have learnt the last 12 months. First, however, we need to figure out where to land a plane to build a base camp and fuel station in the wilderness.

I searched scientific, military, and industry sources to find places where planes have landed near Petermann Gletscher. The first landing, it seems, was a crash landing of an US B-29 bomber on 21 February 1947 at the so-called Kee Bird site. All 11 crew survived, the plane is still there even though it burnt after a 1994/95 restoration effort that got to the site in a 1962 Caribou plane landing on soft ground with a bulldozer aboard that is still there also. A Kee Bird forum contains 2014 photos and, most importantly for my purpose, a map.

Location of Kee Bird and other landing sites in North Greenland near Petermann Gletscher. [From Forum]

Location of Kee Bird and other landing sites in North Greenland near Petermann Gletscher. [From Michael Hjorth]

Michael Hjorth posted the map after visiting the region as the Head of Operation of Avannaa Resources. This small mineral exploration company was searching for zinc deposits and was working out of a camp a few miles to the north of the Kee Bird site and a few miles to the west of Petermann Gletscher. The Avannaa Camp was on the north-western side of an unnamed snaking lake in a valley to the south of Cecil Gletscher, e.g.,

Names of glaciers, capes, islands in Petermann Region over MODIS of Aug.-21, 2012.

Names of glaciers, capes, islands in Petermann Region over MODIS of Aug.-21, 2012.

Here are videos that show Twin Otter, helicopter, and camp operations all at the Avannaa site in 2013 and 2014:


The Avannaa camp of 2013 and 2014 was supplied from a more southern base camp at Cass Fjord that Avannaa Logistics and/or another mineral company, Ironbark.gl apparently reached via a chartered ship.

Cass Fjord Base Camp on southern Washington Land and Kane Basin. Credit: IronBark Inc.

Cass Fjord Base Camp on southern Washington Land and Kane Basin. Credit: IronBark Inc.

A summary of all 2013-14 Washington Land activities both at the Avannaa Camp next to Petermann Gletscher and the Cass Fjord Base Camp adjacent to Kane Basin is contained within this longer video of Michael Hjorth

The mining explorations are based on geological maps that Dr. Peter Dawes of the Geological Survey of Denmark and Greenland provided about 10-20 years ago. These publications contain excellent maps and local descriptions both of the geology and geography of the region as well as logistics. The perhaps most comprehensive of these is

http://www.geus.dk/publications/maps/map1_p01-48.pdf

from which I extract this map that shows both the Cass Fjord and Hiawatha Camps:

Dawes (2004): "Simplified geological map of the Nares Strait region ..." from Thule Air Force Base in the south to the Arctic Ocean in the north with Petermann Gletscher in the center of the top half.

Dawes (2004): “Simplified geological map of the Nares Strait region …” from Thule Air Force Base in the south to the Arctic Ocean in the north with Petermann Gletscher in the center of the top half.

while

http://www.geus.dk/publications/review-greenland-99/gsb186p35-41.pdf

has this photo on how one of these landing strips looks like on a raised beach

dawes2000-fig3

If we do plan future activities at Petermann Gletscher and/or Washington Land and/or areas to the north, then I feel that the Avannaa site may serve as a good semi-permanent base of operation for several years. It is here that Ken Borek Twin Otter landed several times. It is reachable with single-engine AS-350 helicopters that could be stationed there during the summer with a fuel depot to support field work on the ice shelf of Petermann Gletscher and the land that surrounds it. The established Cass Fjord Base Camp to the south would serve as the staging area for this Petermann Camp which has both a short landing strip suitable for Twin Otter and potential access from the ocean via a ship. Access by sea may vary from year to year, though, because navigation depends on the time that a regular ice arch between Ellesmere Island and Greenland near 79 N latitude breaks apart. There are years such as 2015, that sea ice denies access to Kane Basin to all ships except exceptionally strong icebreakers such as the Swedish I/B Oden or the Canadian CCGS Henry Larsen. In lighter ice years such as 2009, 2010, and 2012 access with regular or ice-strengthened ships is possible as demonstrated by the Arctic Sunrise and Danish Naval Patrol boats. International collaboration is key to leverage multiple activities and expensive logistics by land, air, or sea in this remote area of Greenland.

Petermann Gletscher Ocean Station Revisited

Standing on floating Petermann Gletscher last sunday, I called my PhD student Peter Washam out of bed at 5 am via our emergency Iridium phone to check the machine that Keith Nicholls and I had just repaired. We had prepared for this 4 months and quickly established that a computer in Delaware could “talk” to a computer in Greenland to receive data from the ocean 800 m below my feet on a slippery glacier. For comparison the Empire State Building is 480 m high. The closest bar was 5 hours away by helicopter at Thule Air Force Base from where Keith and I had come.

Cabled ocean observatory linked to a University of Delaware weather station on Petermann Gletscher, Greenland on 28 August 2016. View is to the north.

Refurbished ocean observatory linked via cables to a University of Delaware weather station on Petermann Gletscher, Greenland on 28 August 2016. View is to the north.

Remote Petermann Gletscher can be reached by helicopter only of one prepares at least two refueling stations along the way. Anticipating a potential future need, we had placed 1300 and 1600 liters of A1 jet fuel at two points from aboard the Swedish icebreaker Oden in 2015. The fuel was given to Greenland Air with an informal agreement that we could use the fuel for a 2016 or 2017 helicopter charter. Our first pit stop looked like this on the southern shores of Kane Basin

Refueling stop on north-eastern Inglefield Land on 27 August 2016. Air Greenland Bell-212 helicopter in the background, view is to the north.

Refueling stop on southern Washington Land on 27 August 2016. Air Greenland Bell-212 helicopter in the background, view is to the south towards Kane Basin.

Helicopter flight path on 27/28 August 2016 to reach Petermann Gletscher (PG) via southern (Fuel-S) and northern (Fuel-N) fuel stops in northern Inglefield and southern Washington Land, respectively. Background color is ocean bottom depth in meters.

Helicopter flight path on 27/28 August 2016 to reach Petermann Gletscher (PG) via southern (Fuel-S) and northern (Fuel-N) fuel stops in northern Inglefield and southern Washington Land, respectively. Background color is ocean bottom depth in meters.

Upon arrival at the first (northern-most) Peterman Gletscher (PG) station we quickly confirmed our earlier suspicion that vertical motion within the 100 m thick glacier ice had ruptured the cables connecting two ocean sensors below the ice to data loggers above. We quickly disassembled the station and moved on to our central station that failed to communicate with us since 11 February 2016. Keith predicted that here, too, internal glacier motions would have stretched the cables inside the ice to their breaking point, however, this was not to be the case.

My first impression of this station was one of driftwood strewn on the beach of an ocean of ice:

Looks can be deceiving, however, and we found no damage to any electrical components from the yellow-painted wooden battery box housing two 12 Volt fancy “car batteries” at the bottom to the wind sensor on the top. Backed-up data on a memory card from one of two data loggers (stripped down computers that control power distribution and data collections) indicated that everything was working. The ocean recording from more than 800 meters below our feet was taken only a few minutes prior. In disbelief Keith and I were looking over a full year-long record of ocean temperature, salinity, and pressure as well as glacier motions from a GPS. This made our choices on what to do next very simple: Repair the straggly looking ocean-glacier-weather station, support it with a metal pole drilled 3.5 m into the glacier ice, and refurbish the adjacent radar station. We went to work for a long day and longer night without sleep.

Selfie on Petermann Gletscher on sunday 28 August 2016 after 33 hours without sleep. Weather station and northern wall of Petermann in the clouds. It was raining, too.

Selfie on Petermann Gletscher on sunday 28 August 2016 after 33 hours without sleep. Weather station and northern wall of Petermann in the clouds. It was raining, too.

When all was done, University of Delaware graduate student Peter Washam did the last check at 5:30 am sunday morning. Since then our Greenland station accepts Iridium phone calls every three hours, sends its data home where I post it daily at

http://ows.udel.edu

The data from this station will become the center piece of Peter’s dissertation on glacier-ocean interactions. Peter was part of the British hot water drilling team who camped on the ice in 2015 for 3 weeks while I was on I/B Oden responsible for the work on the physical oceanography of the fjord and adjacent Nares Strait. Alan Mix of Oregon State University prepared and led the 2015 expedition giving us ship and helicopter time generously to support our work on the ice shelf of Petermann. Saskia Madlener documented the scope of the 2015 work in a wonderful set of three videos

Ocean & Ice – https://vimeo.com/178289799
Rocks & Shells – https://vimeo.com/178379027
Seafloor & Sediment – https://vimeo.com/169110567

A first peer-reviewed publication on this station and its data until 11 February 2016 will appear in the December 2016 issue of the open-access journal Oceanography with the title The Ice Shelf of Petermann Gletscher, North Greenland and its Connection to the Arctic and Atlantic Oceans.

Men and Women on the Edge 1

EDIT: Original post was too long and rambling. One advice by wise female council, I decided to turn this into two separate posts. This is the first. July 5, 2014.

The “Quiet American” is not a popular book in the United States of America, but to me it described the dilemma and dangers of being American very well. Continue reading

Petermann Ice Island Breaks while Plowing into the Bottom

The Manhattan-sized ice island that last year broke free of Petermann Gletscher in North Greenland plowed into the bottom and broke apart. Force equals mass times acceleration. When 18 giga tons (mass) of moving ice crashes into the ocean’s bottom 200 meters below the surface (acceleration), then something gotta give. And give it did, Continue reading