Canadian Arctic 2017 Expedition

August 30-September 12, 2017

Overview

Building on a successful marine geoscience program onboard the R/V Araon in the Canadian Beaufort Sea in 2013 and 2014, the Korea Polar Research Institute (KOPRI), Natural Resources Canada (NRCan), and MBARI are continuing their scientific collaboration with the undertaking of the 2017 Canada-Korea-USA Beaufort Sea Geoscience Research Program.

The research team, made up of scientists, engineers, and technicians from all three organizations, will be working in the southern portion of the Canadian Beaufort Sea from August 29 to September 13. The Araon is the main research vessel utilized by KOPRI for research and logistics in the Antarctic and Arctic. The Araon is a 110-meter-long icebreaker commissioned by KOPRI and launched in 2009. The scientific design of the ship is impressive with capabilities to undertake integrated multidisciplinary oceanographic, atmospheric, and marine geology studies. Priorities for the upcoming mission will include multi-channel seismic surveys, detailed bathymetric mapping, coring, and ocean and atmospheric science studies.

The R/V Araon is a large icebreaker operated by the Korea Polar Research Institute. Photo: KOPRI.

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Program activities include

  • Multi-channel 2D seismic data acquisition
  • Oceanographic and bathymetric data collection
  • Sub-bottom profiling
  • Sediment coring and microbiological sampling
  • High-resolution multibeam and sub-bottom profiling with an autonomous underwater vehicle (AUV)
  • Bottom-video observations with a remotely operated vehicle (ROV)

The research program will also include three marine mammal observers to implement our vessel-based marine mammal observer program, which encompasses numerous mitigation measures during our five-day multi-channel seismic program.

Scientific goals and objectives

The research collaboration enabling this expedition was established in 2009 with a primary objective to study the geological, geophysical, and oceanographic environment of the Beaufort Sea shelf and upper slope. Our hypothesis is that shelf areas of the Arctic with water depths of less than 100 meters are underlain by permafrost and gas hydrate stability conditions that formed during past glacial periods and are only now being altered by the thermal effects of marine transgression, which may promote their degradation. These shallow shelf areas are widespread and make up nearly 32 percent of the Arctic Ocean.

Map showing the survey location of the 2017 Canadian Arctic Expedition.

Our research will allow for the assessment of the importance of Arctic shelves as past and present sources of methane for the atmosphere, and it will quantify a range of geohazard and environmental processes associated with gas migration and release.

The Beaufort Shelf is an ideal study area for a number of reasons:

  • Significant amounts of thermally disturbed permafrost gas hydrate are known to exist in the subsurface;
  • Gas venting has been documented in association with unique physical features on the seafloor (i.e., active submarine pingo-like features, pockmarks, sub-marine slope failures, and permafrost taliks), suggesting there are unique point sources and transitional pathways for fluid and gas movements from decomposing gas hydrates; and
  • The surface sediments in this area are predominantly fine-grained, permitting collection of good sediment cores to enable stratigraphic, biostratigraphic, and geochemical studies (this is rare in the Arctic Ocean).

We believe that research in the Beaufort Sea will contribute to the understanding of other larger Arctic shelves.

In previous research cruises (in 2003, 2010, 2012, 2013, 2016) in the Canadian Beaufort Sea, MBARI and GSC have documented the existence of methane gas release from several sites on the continental shelf and slope. Most of the venting methane gas is believed to be derived from the decomposition of permafrost or gas hydrate deposits that exist underneath the arctic continental shelf.

Past AUV and ROV surveys have also revealed the existence of an unusual concentration of distinct morphologic features including scars of large submarine landslides, isolated topographic mounds—including some associated with fluidized mud deposits, known as mud volcanoes—and the existence of glacially derived marine deposits. All these features are potential marine geohazards. The impact of submarine permafrost formation and/or degradation on the formation of these seafloor structures remains poorly understood. However, the earlier discoveries have already substantially advanced our understanding past glacial extents as well as the process that may be modifying the shape of the Arctic seafloor now.

MBARI’s mapping AUV being recovered onto the CCGS Sir Wilfrid Laurier in the Beaufort Sea in 2016. Photo: MBARI.


MBARI’s Mini ROV being deployed from the CCGS Sir Wilfrid Laurier in the Beaufort Sea in 2016. Photo: NRCan.


A perspective view of the seafloor bathymetry shows an example of a landslide previously mapped on the shelf edge in the Beaufort Sea. Photo: MBARI.

A perspective view of a mud volcano mapped in 2016 on the continental shelf in the Beaufort Sea. Below is a sub-bottom profile, showing sediment layering, or lack of, along a survey line mapped by the AUV. Photo: MBARI.

Logbook

Pingo-like features and mud volcanoes

Over the last few days we conducted three ROV dives and two AUV surveys at areas of geologic interest on the eastern Mackenzie Shelf that are called pingo-like features and mud volcanoes.

Report from the terrestrial field party

The 2017 Arctic field program also includes a terrestrial component with Scott Dallimore and Stephen Wolfe from the Geological Survey of Canada (GSC) examining the coastal geology of the northern Yukon.

Arrival and science preparations

The expedition kicked off with members of the three science teams from KOPRI, MBARI, and the GSC assembling in Barrow, Alaska, and transferring, via helicopter, to the ship.

Revisiting Herschel Island

The Araon science program began immediately upon crossing the Canadian border with targeted multi-beam and sub-bottom mapping of an interesting trough feature that occurs on the Yukon shelf.