Canadian arctic glacier retreat – From a Glaciers Perspective

Yelverton Glacier (Y) and De Vries Glacier (D) in 1999 and 2018 Landsat images. Red arrows and red dots indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak, the boundary of this area is marked by orange dots. Purple dots mark the snowline.

Yelverton Glacier is an outlet glacier from an ice cap on Northern Ellesmere Island. White and Copland (2019) identified an 85% reduction in are of eight floating ice tongues in the Yelverton Bay area. They further observed that many of the glacier including Yelverton lost a substantial area of melange that had protected the glacier fronts from contact with open water. The melange is comprised of icebergs and mulit-year sea ice and is referred to as sikussak. Here we examine Landsat images from 1999-2018 to identify the retreat of Yelverton Glacier and the loss of sikussak.

In 1999, the sikussak extends to the end of the Yelverton Glacier inlet, while the glacier terminus is 4.5 km up the inlet. De Vries Glacier terminates adjacent to the northern tip of the peninsula separating De Vries and Yelverton. In 2000, there is no change in the terminus or sikussak, the snowline is at 900 m. In 2002, the terminus region and sikussak remain unchanged, the snowline is again close to 900 m. By 2015, Yelverton Glacier has retreated to its grounding line. The sikussak that had existed is gone. In 2018, the terminus is exposed to open water and has retreated 8 km since 1999, the snowline is at 900 m. The area of sikussak that had been 6 km long has not returned and persisted since it disappeared. Pope and Copland (2012) noted the loss of multi-year land fast sea ice in the region beginning in 2005 and concluding with total loss by 2010 driven by warming. This same climate change has also driven the retreat of Trinity Wickeham Glacier and Devon Ice Cap that also released new islands. The Canadian Arctic Islands have seen widespread glacier area/mass balance loss particularly during the last two decades ( Noël, 2018).

Yelverton Glacier (Y) and De Vries Glacier (D) in 2002 and 2015 Landsat images. Red arrows indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak.

Yelverton Glacier (Y) and De Vries Glacier (D) in 2000 and 2015 Landsat images. Red arrows indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak.

The northern coast of the Devon Ice Cap with Lady Ann Strait at the top in a 2000 and 2017 Landsat image indicating the development of islands at Cape Caledon, at yellow arrows. See map below.

The Devon Ice Cap on Devon Island in the Canadian Arctic ice cap’s area has an area of 15,000 km², with a volume of 3980 km³. The ice cap has been the focus of an ongoing research program led by the University of Alberta Arctic and Alpine Research Group. The mass balance from 1960-2009 was cumulatively -5.6 m, with nine of the eleven most negative years occurring since 1998. Noel et al (2018) update this observation noting that Canadian Arctic ice caps have been losing mass for decades and that mass loss accelerated in 1996. This followed a significant warming (+1.1∘C), which increased the production of meltwater. This has led to widespread area losses. White and Copland (2018) quantify the change in the areal extent of 1773 glaciers on Northern Ellesmere Island from 1999 to 2015. They found regional glacier area decreased by ∼6%, with not a single glacier increasing in areal extent.

East of Belcher Glacier, a large retreating tidewater outlet of the Devon Ice Cap, maps indicate a glacier terminating at Cape Caledon, a series of rocky Points on the southern side of the Lady Ann Strait. Today the Cape Caledon Glacier no longer reaches these rocky Points that have now become islands. Here we examine Landsat images from 2000 to 2018 to illustrate the changes.

In 2000 the Cape Caledon Glacier terminates along its north side on three rocky points, yellow arrows, while the eastern margin is pinned on the northeastern most of the Points and extends nearly due south to another rocky Point, yellow arrow. In 2002 little has changed on the northern or eastern margin. By 2017 the glacier has separated from the three rocky Points on the northern margin, each is now a new island. The mid-August 2017 image indicates that the snowline is particularly high, with none of the Cape Caledon Glacier in the accumulation zone. This supports what has been observed in terms of significant changes in the nature of the firn due to increased meltwater infiltration in the region (Gascoin et al 2013). The eastern margin has retreated along most of its length, but remains attached to the rocky Point on the southern margin. In 2018 the islands remain separated from the glacier, but have some sea ice still around them. The eastern margin that had terminated at the northeast most rocky Point has retreated from 500-700 m along nearly the entire front, except for the very southern margin. The generation of new islands is a process occurring across the Arctic as glaciers recede (Ziaja and Ostafin, 2018).

The northern coast of the Devon Ice Cap with Lady Ann Strait at the top in a 2002 and 2018 Landsat image indicating the development of islands at Cape Caledon, at yellow arrows.

Map of Cape Caledon on the north coast of the Devon Ice Cap

The northern coast of the Devon Ice Cap with Lady Ann Strait at the top in a 2017 Landsat image indicating the development of islands at Cape Caledon, at yellow arrows, surrounded by some sea ice.