Terra Nivea Ice Cap Expanding Bedrock Outcrops and Proglacial Lakes

On June 8, 2023April 19, 2024 By mspeltoIn Canada glacier retreat

Terra Nivea Ice Cap in Sentinel false color images from 2017 and 2022. Point A=bedrock outcrops expanding. Point L=expanding proglacial lakes. Red arrow=supraglacial stream chanels, yellow arrow=annual layers, green arrow=location where ice cap will separate.

Terra Nivea Ice Cap is the southern most Ice Cap in North America, on the Terra Incognita Peninsula of Baffin Island. Mercer (1956) noted that the ice cap accumulation during most years was via superimposed ice, though some years snow did endure at the top of the ice cap. Paspodoro et al (2015) observed a 34% reduction in ice cap area from 1958-2014 with an acceleration after 2007. Here we note a lack of retained snow, firn or superimposed ice on the northern portion of the ice cap in 2017 and 2022. The lack of retained accumulation as snow or ice results in rapid thinning that is leading to bedrock expansion within and at the margin of the ice cap and the expansion of peripheral proglacial lakes.

Point A marks specific locations where bedrock areas amidst the ice cap are expanding. This expansion will lead to separation of the ice cap at the green arrows soon. The ice cap was 1.9 km wide at this point in 2017 and 1.5 km in 2022. Point L marks locatsions of proglacial lake expansion. The yellow arrows indicate annual layers even at the summit area, which would not be visible if superimposed ice was forming. The red arrows indicate supraglacial stream channel that lead all the way to the summit region. For an ice cap retaiining firn or superimposed ice, the channels would begin below that margin. This illustrates that during the the 2017-2022 there was no retained accumulation on Terra Nivea Ice Cap. This is true of the rest of the ice cap as well. Here in order to better visualize change, the focus is just on the northern portion.

This same story is playing out on Grinnell Ice Cap.

Terra Nivea Ice Cap in Sentinel false color images from 2017 and 2022 illustraing separation region. Point A=bedrock outcrops expanding. Point L=expanding proglacial lakes. Green arrow=location where ice cap will separate.

Penny Ice Cap NW Thinning and Retreat Evident

On July 7, 2019April 25, 2024 By mspeltoIn Canada glacier retreat3 Comments

The Northwest (NW) and Northnorthwest (NNW) outlet of the Penny Ice Cap in 1991 and 2019 Landsat images. Red arrow indicates the 1991 terminus location. Point 1 is a large proglacial, Point 2-4 are areas of emerging and expanding bedrock amidst the ice cap.

The two largest outlet glaciers of the NW quadrant of the Penny Ice Cap feed the Isurtuq River. In 1991 both outlet glaciers terminated at 600 m. Schaffer et al. (2017) noted a substantial reduction in velocity of the six largest outlet glaciers of the Penny Ice Cap from 1985-2011, 12% per decade. This is driven by mass balance losses, which drive thinning and retreat as well. Here we examine the changes from 1991-2019 of the Northwest (NW) and Northnorthwest (NNW) outlet of the Penny Ice Cap. The summer of 2019 is shaping up to feature substantial mass balance losses.

In the 1991 Landsat image the NW outlet reaches the Isurtuq River. The large 7 km² proglacial lake #1 is impounded by the glacier, it is mostly covered by lake ice in this image. At Point #3 there is no bedrock that has emerged. The NNW outlet terminates 1 km south of the Isurtuq River, upglacier Point #2 is a single bedrock outcrop and Point #4 is barely evident. In 2000 the NW outlet has receded from the river, the proglacial lake is still 7 km² and Point #3 has no evident bedrock. The NNW outlet has receded 100-200 m and bedrock at Point #2 and 4 are more evident. In 2016 the proglacial lake has diminished and now is several small lakes. At Point 3 bedrock is evident. At Point #2 there are two areas of bedrock covering 0.25 km². The snowline in 2016 is above this portion of the icecap. In 2019 the NW outlet has retreated 500 m, proglacial lake #1 has three separate parts that total less than 2 km². Bedrock at Point #2-4 has expanded significantly indicating ice cap thinning. On June 30 2019 the snowline is already above this section of the ice cap, +1100 m with two months of melting to come. Point #2 has an exposed bedrock area of 0.8 km². Look for a merging of the bedrock at Point 2 and further expansion at 3 and 4. The high snowline at +1100 m, for this early in the summer was also observed at Fork Beard Glacier just east of Penny Ice Cap and is due to very warm temperatures in June in the region.

Way (2015) noted that the Grinnell Ice Cap also on Baffin Island, has lost 18% of its area from 1974 to 2013 and that the rate of loss has greatly accelerated due so summer warming. Grinnell Ice Cap also has seen a loss of snowpack even at its crest.

The Northwest and Northnorthwest outlet of the Penny Ice Cap in 2000 and 2016 Landsat images. Red arrow indicates the 1991 terminus location. Point 1 is a large proglacial, Point 2-4 are areas of emerging and expanding bedrock amidst the ice cap.

Map of the region

Fork Beard Glacier, Baffin Island High June 2019 Temperatures and Snowline

On July 1, 2019April 25, 2024 By mspeltoIn Canada glacier retreat

Fork Beard (F) and Nerutusoq Glacier (N) Baffin Island on June 1, 2019, June 18, 2019 Sentinel images and June 30 Landsat image. Purple dots indicate the snowline.

Fork Beard Glacier (F) is an outlet glacier of a mountain glacier complex just southeast of Penny Ice Cap on Baffin Island. Nerutusoq Glacier (N) also drains from the same complex. Here we examine the rapid rise of the snowline from June 1 to June 30, 2019. This 30-day period at nearby Pangnirtung featured four days with record temperatures for that date June 5 (15.1), June 11 (13.5) and June 12 (13.6), and June 19 (14.4). There were 14 days with a maximum temperature above 10 C. Landsat images are utilized to identify the retreat and separation of Fork Beard Glacier and Nerutusoq Glacier and several neighboring glaciers from 1990-2018. Gardner et al (2012) and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years in the region, the period of record, and they identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. This has led to fragmentation of Coutts Ice Cap and loss of snowpack at Borden Ice Cap and disappearance of ice caps near Clephane Bay all on Baffin Island.

In late July of 1990 Fork Beard Glacier terminates near the top of a steep slope at 650 m, red arrow. At Point 1 and 2 tributaries connect to the main stem of two unnamed glaciers adjacent to Fork Beard Glacier. Nerutusoq Glacier terminates at 700 m. The snowline in mid August of 1990 on Fork Beard and its adjacent glacier to the southeast is 1050 m. In 2000 at Point 1 and 2 the tributaries still connect. The terminus of Fork Beard and Nerutusoq Glacier have retreated 200-300 m since 1990. The snowline in this mid-August image is at 1150 m. By 2018 Fork Beard Glacier has retreated 600-700 m and now terminates at an elevation of 750 m. Nerutusoq Glacier has retreated 600-700 m and now terminates at an elevation of 825 m. In this late July image the snowline on Fork Beard and the adjacent glacier to the southeast (S) is again at 1050 m. At Point 1 and 2 tributary glaciers have separated from the main stem glaciers. In Sentinel images from 2019 the snowline on Fork Beard Glacier and Nerutusoq Glacier is at 800 m on June 1 rising rapidly to 1100 m by June 18. On June 30 the snowline has risen to 1150 m. from This is a higher elevation than typically seen a month or two months later in the melt season during other years. The retreat in the region is driven by warmer temperatures and rising snowlines. The glacier of Baffin Island are already primed for another poor year in 2019.

Fork Beard (F) and Nerutusoq Glacier (N), Baffin Island in 1990 and 2018 Landsat images. Red arrow indicates 1990 terminus, yellow arrow 2018 terminus, purple dots the snowline.

Map of the region indicating flow on Fork Beard, Nerutusoq and two unnamed adjacent glaciers. Red arrow indicates 1990 terminus of Fork Beard at top of steep bench.

Fork Beard (F) and Nerutusoq Glacier (N), Baffin Island in 2000 Landsat image. Red arrow indicates 1990 terminus and purple dots the snowline.

Coutts Ice Cap, Baffin Island Fragmentation

On June 14, 2018April 27, 2024 By mspeltoIn Canada glacier retreat

Coutts Ice Cap in Landsat images from 1986 and 2017. The terminus location of the main glacier terminating in the large lake is indicated by dots. Tributary Glaciers 1-6 represent locations where glaciers have separated or a glacier has retreated from a lake.

Coutts Ice Cap is on between Coutts Inlet to the west and Buchan Gulf to the east on the north shore of Baffin Island near its northeastern tip (see map below). Here we are focused on a group of glacier that descend into a basin, that I refer to as Coutts Basin and Coutts Basin Lake. Gardner et al (2012) and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years in the region, the period of record, and they identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. This led to surface lowering of up to 1 m/year on all ice masses on Baffin Island and Bylot Island between 1963 and 2006 (Gardner et al. 2012).

In 1986 the Tributary Glacier 1 (TG1), flows into the Coutts Lake basin joining with TG2. TG3 feeds into the Coutts Basin glacier system. TG4 has a significant piedomont lobe but terminates short of the Coutts Basin Lake. TG5 reaches the northern shore of Coutts Basin lake. TG6 drains into a secondary lake above the main Coutts Basin. The main terminus of the Coutts Basin Glacier, red dots extends east to west across the lake. In 1999 the snowline is higher and there are minor changes, but retreat is limited and none of the glaciers have separated. In 2016 the snowline is very high at 1500 m, leaving only a small part of the ice cap with snowcover. The high snowline in August 2016 have observed on Borden Ice Cap and Penny Ice Cap and have driven thinning and retreat there as well. TG1 no longer merges with TG2. There is a separation of the glacier lobes at TG2. TG3 no longer substantially feeds the Coutts Basin. TG4 has thinned and retreated from near the short of Coutts Basin Lake. TG5 has receded from the lake shore. TG6 has retreated from the upper lake. In 2017 the margin of the main Coutts Basin Glacier no longer extends across the lake, yellow dots. The snowline in August 2017 is at 1100 m lower than 2016.

Way (2015) noted that summer temperatures have warmed more than 1 C after 1990 on the Cumberland Peninsula at the south end of Baffin leading to a 18-22% decline of Grinnell and Terra Nivea Ice Cap.

Coutts Ice Cap in Landsat images from 1999 and 2016. The terminus location of the main glacier terminating in the large lake is indicated by dots. Locations 1-6 represent locations where glaciers have separated or a glacier has retreated from a lake.

Map of the region indicating Cape Jameson (CJ), Coutts Inlet (CI), Buchan Gulf (BG), North Arm (NA), Coutts Basin Lake (CBL) and Coutts Ice Cap (CIC).

Borden Peninsula Ice Caps, Baffin Island Snowcover Where Art Thou

On May 11, 2017April 29, 2024 By mspeltoIn Canada glacier retreat

Borden Peninsula Ice Cap in 1997 and 2016 Landsat images. Purple dots indicate the transient snowline. Orange arrows indicate specific location of glacier thinning, retreat or area loss.

The Borden Peninsula is in the northeastern most section of Baffin Island. Here we examine an ice cap that is on the edge of Lancaster Sound in Sirmilik National Park. We use Landsat imagery from 1997 through 2016 to identify change. This compliments the examination of other Baffin Island Ice Caps: Dexterity, Clephane Bay, Grinnell, Barnes and Penny. Gardner et al (2012) and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years, the period of record and they identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island.

In 1997 the transient snowline late in the ablation season is averages 1020 m. Two glaciers the Ikkarlak Glacier Point 2 and the next glacier to the southeast, downstream of Point 6 both reached tidewater. lat in the ablation season of 2001 the transient snowline again average 1020 m. In 2016 there is no retained snowpack. At Point 1 the arrow indicates an outlet glacier than has thinned where it connects to the main ice cap from 600 m to 250 m. At Point 2 the Ikkarlak Glacier that had reached tidewater in 1997 and 2001 no longer reaches the coast. At Point 3 a tributary glacier has been reduced in length and width. At Point 4 the width of the outlet glacier has been reduced by 50%. At Point 5 in 1997 the glacier reached within 200 m of the coast and in 2016 the glacier terminates 500 m from the coast. At Point 6 areas of new bedrock amidst the icecap have developed and expanded. At Point 7 two outlet glaciers merged ain 1997 and in 2016 are now separated with an expanding bedrock region between the glacier tongues. The Uqanguaq Glacier at Point 8 has retreated from a terminal moraine, indicating a retreat of 600 m from this moraine with 300 m of retreat since 1997. The lack of retained snowcover is similar to that seen at other Baffin Island Ice Caps recently Dexterity, Clephane Bay, and Grinnell. Way (2015) noted that summer temperatures have warmed more than 1 C after 1990 in the region and that has led to disequilibrium with climate for Grinnell and Terra Nivea Ice Cap. The Borden Peninsula Ice Cap is retreating less than the ice caps noted in the southern part of Baffin Island.

Borden Peninsula Ice Cap in 2001 Landsat image. Purple dots indicate the transient snowline.

Borden Peninsula Ice Cap in July 31, 2015 Landsat image. Purple dots indicate the transient snowline at 1060 m.

Penny Ice Cap Northern Outlet Retreat, Baffin Island

On January 20, 2017May 1, 2024 By mspeltoIn Canada glacier retreat

Penny Ice Cap Northern Outlet Glacier #43 in 1989 and 2016 Landsat images. Red arrow indicates 1989 terminus, yellow arrow 2016 terminus. Two peripheral ice masses are at Point A and B.

The primary northern outlet from the Penny ice Cap is an unnamed glacier, noted as #43 in the recent study by Van Wychen et al (2015). it is one of two large tidewater outlet glaciers on Baffin Island. Here we examine the response driven by climate change of this glacier from 1989 to 2016 using Landsat and Sentinel Imagery. Van Wychen et al (2015) observe that it is one of the two largest discharging glacier on the island and the Penny Ice Cap, with Coronation Glacier. They observed peak velocities of over 100 m/year, 20 km upglacier of the terminus, declining to less than 20 m/year in the lower 10 km of the glacier. Zdanowizc et al (2012) noted that in recent years the ice cap has experienced heightened melt, a longer melt season and that little retained snowpack survives the summer, that most of the retained accumulation is refrozen meltwater or superimposed ice. Geodetic methods indicate surface lowering of up to 1 m/year on all ice masses on Baffin Island and Bylot Island between 1963 and 2006 (Gardner et al.2012).

In 1989 the glacier terminated 1 km south of a terminal moraine peninsula that extends most of the way across the fjord. By 2014 glacier retreat is accompanied by the formation of two deltaics areas in front of the glacier, orange arrows in images below. It is not clear if these are islands, a shoal in the fjord or the head of the fjord. Retreat from 1989 to 2016 is 900 m on the west side of the terminus, 600 m on the east side. Two peripheral ice masses at Point A and B lack snowcover in 2016 and have lost area as well. Extensive transverse crevasses develop in the last 700 m upglacier of the terminus, indicating the force imbalance that enables and enhances calving at the ice front, yellow arrow. The reduced retained snowpack on the Penny Ice Cap is leading to reduced discharge and glacier retreat. With a high snowline in 2016 indicated by the lack of retained snowpack on ice masses at Point A and B, it is clear this trend is ongoing. The impact is less dramatic than those noted in the Clephane Bay area of Baffin Island.

Penny Ice Cap Northern Outlet Glacier in 2016 Sentinel 2 image. Yellow arrow indicates crevassing triggered by calving processes, orange arrows developing deltaics areas.

A 2014 Google Earth image of glacier front. Red arrow indicates 1989 terminus, yellow arrow 2016 terminus and orange arrows deltaic land areas building.

Coronation Glacier, Baffin Island Retreat Leads to Building a New Island

On January 9, 2017May 1, 2024 By mspeltoIn Canada glacier retreat3 Comments

A Landsat image from 1989 and a Sentinel 2 image from2016 illustrate the retreat of Coronation Glacier. Red arrows indicate the 1989 terminus and yellow arrows the 2016 terminus location. Purple numbers 1-5 indicate locations of tributary retreat or thinning. Purple numbers 6-9 are icecaps that did not retain snowcover in 2016.

Coronation Glacier is the largest outlet glacier of the Penny Ice Cap on Baffin Island. The glacier has an area of ~660 square kilometers and extends 35 km from the edge of the ice cap terminating in Coronation Fjord. On January 10, 2017 an Art Exhibit “Into the Arctic” by Cory Trepanier opens at the Canadian Embassy in Washington DC, the first stop in a two year North American tour. The exhibit features some amazing paintings of Coronation Glacier (see below). Here we examine the response driven by climate change of this glacier from 1989 to 2016 using Landsat and Sentinel Imagery. Van Wychen et al (2015) observe that it is the largest glacier from any of the Baffin Island Ice Caps with discharge greater than 10 Mt/year. They observed peak velocities of 100-120 m/year in the descent from the main ice cap into the main glacier valley. The velocity in the terminus section is ~30 meters/year. Syvitski (1992) noted that Coronation glacier retreated at an average rate of 12 meters per year from 1890-1988. Zdanowizc et al (2012) noted that in recent years the ice cap has experienced heightened melt, a longer melt season and that little retained snowpack survives the summer, that most of the retained accumulation is refrozen meltwater (superimposed ice). This has helped lead to firn temperatures at 10m depth near the summit of Penny Ice Cap to warm by 10 °C between the mid-1990s and 2011, (Zdanowizc et al (2012). Geodetic methods indicate surface lowering of up to 1 m/year on all ice masses on Baffin Island and Bylot Island between 1963 and 2006 (Gardner et al.2012).

Cory Trepanier Great Glacier painting, which is of Coronation Glacier.

In 1989 Coronation Glacier terminates at the red arrow, where the main outlet stream has created a pair of small deltaic islands on the northern side of the fjord. By 1998 the terminus has retreated from both islands, with the northern one already having disappeared. There is a plume of glacier sediments in the fjord from the main river outlet emanating from below the glacier is near the center of the glacier. There has not been significant retreat on the south side of the glacier terminus. In 2002 both islands are gone, most of the retreat is still on the northern side of fjord. The plume of glacier sediments in the fjord from the main river outlet remains near the center of the glacier. In 2016 a new deltaic island has formed near the southern edge of the margin, indicating a shift in the position of the main river outlet emanating from below the glacier, this is also marked by a large plume. The island formed is larger than those observed in 1989 or 1998. The nature of the loosely consolidated glacier sediments deposited in a fjord is to subside/erode after the sediment source is eliminated. The retreat of the glacier insures that this will occur soon to the island here. The size of the island gives it potential to survive, based on satellite imagery. A visit to the island would be needed to shed light on its potential for enduring. Cory Trepanier is hoping to return for more paintings, which will illustrate better the change to us than a satellite image can. Retreat from 1989 to 2016 has been 1100 m on the northern side of the fjord and 500 m on the south side of the fjord. The average retreat of 800 m in 27 years is over 30 m/year, much faster than the 1880-1988 period. Locations 1-5 are tributaries that have each narrowed or retreated from the main stem of the glacier.

Closeup of the Coronation Glacier terminus and the new island in 2016, Sentinel 2 image.

The other noteworthy change is the lack of snowpack retained at locations 6-9 in the 2016 Sentinel image on small ice caps adjacent to Coronation Glacier in 2016. This continues a trend observed in 2004, 2009, 2010 and 2012 and that Zdanowizc et al (2012) also noted, 2009 image below. The high snowline is also evident on Grinnell Ice Cap The driving force has been an increase in temperature and this has caused mass losses on ice caps throughout the Canadian Arctic (Gardner, et al. 2011) and (Sharp et al, 2011).

Sequence of Landsat images indicating terminus positions. Red arrow is the 1989 terminus position and yellow arrow the 2016 terminus position.

2009 Landsat image of Coronation Glacier indicating lack of retained snowcover on surrounding ice caps.

Barnes Ice Cap, Baffin Island Evident Response to Climate Change

On November 18, 2016May 1, 2024 By mspeltoIn Canada glacier retreat1 Comment

Barnes Ice Cap transect and closeup of divide area in August 2016. Black dots indicate summit divide of the ice cap. Notice the channels extending away from the divide. These are not stream channels, as they are too wide, but they are meltwater formed valleys that are preferred pathways for the meltwater transport.

Barnes Ice Cap located in the center of Bafﬁn Island, Canada covers an area of ~5800 km2. The ice cap is approximately 150 km long, 60 km wide and has maximum ice thickness of ~730 m and a maximum ice elevation of 1124 m above sea level (asl) at the summit of the north dome (Andrews, 2002). They also note a retreat of the southeast margin of 4 m/year from 1961-1993 on the southeast margin (Jacobs et al 1997). Dupont et al (2012) identified that the melt season increased from 66 days fro the 1979-87 period to 87 days from 2002-2010. They also noted that ICESat altimeter data indicated the thinning of the BIC at a mean rate of 0.75 m/year for the 2003–2009 period. Gilbert et al (2016) Figure 5 indicates the ELA was at 950 in the 1960-80 period and is at 1100 m from 2002-2010 this leaves a limited accumulation zone area. observe that Barnes Ice Cap has nearly lost its accumulation area over the last 10 years, in part due to the longer melt season. The glacier does tend to not retain snowcover the accumulation zone consists of superimposed ice at the crest. Papasodoro et al (2016) noted that glacier wide balances were −0.52 m w.e./year from 1960 to 2013 and doubled to −1.06m w.e./year from 2005 to 2013. They also The drainage channel development suggests meltwater transport from versus refreezing of meltwater in 2016.

Landsat comparison of the northwest margin of the Barnes Ice Cap in 1990 and 2016. Red arrows indicate terminus locations in 1990. Purple arrows indicate an area of stream development parallel to the ice front. The bright area at the margin of the ice cap is Pleistocene ice (Andrews, 2002).

Here we examined Landsat imagery from 1990-2016 to illustrate the retreat of the northwest region of the icecap and to take a look at the 2016 melt features and lack of any retained snowcover on the ice cap. In 2016 the melt channels from the divide at the crest of the ice cap are impressive. There is no retained snowcover at the summit of the ice cap even on August 9th with several week left in the melt season. The melt pathways visible in the imagery from 2016 extend 10 km downslope from the crest of the icecap. In 1990 the ice cap terminated at the red arrows, this included contact with a peninsula in Nivlalis Lake and an island in Conn Lake. By 2011 and 2014 the glacier had retreated from the locations. In 2016 the total retreat of the margin has been 600 m at Nivalis Lake, 1100 m at the island in Conn Lake and 450 m further east at the red arrow halfway to Bieler Lake. This is a slow retreat rate compared to many glaciers, but represents a much higher rate than before 1990, with rates of 18-42 m/year. There is a new section of river parallel to the ice cap margin between Conn and Bieler Laker.

2011 Landsat image of northern margin indicating retreat from the 1990 postiion red arrows.

2014 Landsat image of northern margin indicating retreat from the 1990 postiion red arrows.

Clephane Bay Ice Cap, Baffin Island Being Erased from Map

On May 20, 2016May 2, 2024 By mspeltoIn Canada glacier retreat, climate change glacier retreat

Comparison of 1995 and 2014 Landsat images of ice caps A, B, C, D and E. Pink arrows indicate where A, B and E separated. C and D have disappeared. F is an outlet glacier with a retreating terminus.

The southern part of the Cumberland Peninsula on Baffin Island features many small ice caps. Here we examine the disappearance of two and the separation of two others from 1995 to 2014. Way (2015) noted that on the next peninsula to the west, Terra Nivea and G rinnell Ice Cap had lost 20% of their area in the last three decades. The retreat and disappearance of ice caps in the area have led to a INSTAAR project at UColorado-Boulder examining vegetation that had been buried and is now being exposed. Gardner et al 2011 and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years, the period of record. They identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. This is causing ice caps like Dexterity and those around Clephane Bay to melt away

In 1995 ice caps A-E are each a single coherent ice cap, there are narrow points of connection between sections on A, B and E. Ice Caps C and D are simple ice caps between 500 and 800 m across on their widest axis. The terminus of the outlet glacier at F is an expanded lobe. Only Ice Cap A has a significant area above 800 m. The rate of loss from 1995 to 2002 is not as rapid as after, C and D still exist, A,B and E are still connected as a contiguous ice mass. In 2013 ice cap C and D are gone. The snowline is generally above A, B and E with only a small stripe of retained snow on each. Ice cap A, B and E have each separated into multiple parts. In 2014 there is no retained snow on the ice caps, pink arrows indicate the location of separation for ice caps A,B and E. In 2014 the terminus lobe at Point F has lost half of its area, retreat in distance will not accelerate. The lack of retained accumulation most years indicates no accumulation zone and the ice caps cannot survive without that. The only clear image in 2015 indicates a snowcover in August, but this appears to be from a summer snow event.

Canada Toporama map of the region.

2002 Landsat image limited retained snowpack

2013 Landsat image no retained snowpack.

2015 Landsat image, appears that a summer snowstorm has spread snow across ice covered regions above 500 m.

Auyuittuq National Park Ice Cap Downwasting, Baffin Island

On July 28, 2015May 2, 2024 By mspeltoIn Canada glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations, Uncategorized

Just south of the Penny Ice Cap on Baffin Island in Auyuittuq National Park there are a large number of small ice caps. We focus on three of these ice caps east of Greenshield Lake. The region has been experiencing rapid ice loss, with 50 % of the ice cap area lost in the last few decades (Miller et al, 2008). Miller et al (2008) also observe that these are thin and cold glaciers frozen to their beds with limited flow. Way et al (2015) observed the loss of 18-22% of two larger ice caps on Baffin Island, Grinnell and Terra Incognita. The ice cap losses are due to reduced retained snowpack. Zdanowicz et al (2012) found that starting in the 1980s, Penny Ice Cap entered a phase of enhanced melt rates related to rising summer and winter air temperatures across the eastern Arctic. In recent years they observed that 70 to 100% of the annual accumulation is in the form of refrozen meltwater. However, if the snowline rises above the ice cap consistently, as happened at Grinnell Ice Cap than there is no firn to retain the meltwater and superimposed ice formation is limited. Meltwater has difficulty refreezing on a glacier ice surface. The rise in temperature is illustrated by a figure from Way et al (2015), below

Map of region south of Penny Ice Cap from Canadian Topographic maps.

Figure From Way et al; (2015)

In the 1998 Landsat image the two northern ice caps, with E and F on them, have very little retained any snowpack, but significant firn areas. The larger ice cap has retained snowpack adjacent to Point A and considerable firn area as well. There is a trimline beyond the glacier margin apparent west of Point B due to recent retreat, but otherwise trimlines are not immediately evident. In 2000 the two northern ice caps again have very little retained snow, and the larger ice cap retained snow near Point A. In the 2013 Google Earth image black arrows on the image indicate trimlines recently exposed by glacier retreat. There is no evident retained snow, and no retained firn is even evident. This suggests the ice caps lacks an accumulation zone. A close up view, illustrates many years of accumulation layers now exposed, note the linear dark lines, black arrows. The second closeup view illustrates the area around Point E and D that has been deglaciated. There also are some new areas of expanded bedrock such as near Point A on the larger ice cap. The 2014 Landsat image indicates the bedrock has expanded at Point A. At Point B an area of bedrock is expanding into the ice cap. At Point C the lake has expanded at. Ice has melted away from Point D and E. At Point F a new area of bedrock has emerged within the ice cap. At Point J the new bedrock seen in the 2013 Google Earth image has now expanded to the margin of the ice sheet. These changes are a result of a thinning ice cap, largely due to increased ablation. The lack of retained snow cover or firn confirms there is not a consistent accumulation zone and that these ice caps cannot survive current climate (Pelto, 2010).

1998 Landsat image

2000 Landsat image

2013 Google Earth Image

Google Earth Closeup

2014 Landsat image

Snow Deficit on Grinnell Ice Cap, Baffin Island, Canada

On May 1, 2015May 3, 2024 By mspeltoIn Canada glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations, Uncategorized

The Grinnell Ice Cap Is located on the Terra Incognita Peninsula on Baffin Island. The name suggests the reality that this is a not often visited or studied region. Two recent studies have changed our level of knowledge. Way (2015) notes that the ice cap has lost 18% of its area from 1974 to 2013 and that the rate of loss has greatly accelarated and is due to summer warming, declining from 134 km2 in 1973-1975 imagery to 110 square kilometers in 2010-2013 images. Papasodoro et al (2015) report the area in 2014 at 107 km2 with a maximum of elevation of close to 800 m. The location on a peninsula on the southern part of the island leads to higher precipitation and cool summer temperatures allowing fairly low elevation ice caps to have formed and persisted. Way (2015) in the figure below indicates the cool summer temperatures have warmed more than 1 C after 1990. Recent satellite imagery of snowcover and ICESat elevation mapping suggest little snow is being retained on the Grinnell Ice Cap since 2004. Papasodoro et al (2015) identify a longer mass loss rate of -0.37 meters per year from 1952-2014, not exceptionally different from many alpine glaciers. They further observed that from 2004-2014 this rate has accelerated to over -1 meter per year, including a thinning rate above 1.5 meters along the crest of ice cap. This can only be generated by net melting not ice dynamics. Further such rapid losses will prevent retaining even superimposed ice. Here we examine Landsat imagery from 1994 to 2014 to illustrate glacier response.

Grinnell Ice Cap in Google Earth

From Way (2015)

The red arrows in each image indicate areas of small nunataks that have begun to expand in the last decade. The yellow and green arrows indicate specific locations on the western margin of the ice cap where lakes are developing. Point A-D note specific locations adjacent to ice cap outlet glaciers. In 1994 the late August image indicates snowcover across most of the ice cap. The green arrow is at the northern end of a narrow lake. The yellows arrows are at the northern and southern end of a narrow ice filled depression. The nunatak area exposed at the red arrows is limited. At Point C the terminus is tidewater. In 2000 snow pack covers 40% of the ice cap. A small lake is developing at the yellow arrows. The glacier reaches the ocean at Point C and D. The glacier extends south of Point A and the outlet glacier at Point B is over a 1.2 km wide. In 2012 a warm summer led to the loss of all but snowpack on the glacier. At the red arrows the nunataks have doubled in size. At the yellow arrows a 2.5 km long lake has developed. At the green arrow a lake that has developed, is now separated from the glacier margin by bedrock. The glacier now terminates north of Point A. In 2014 again snowcover is minimal with two weeks left in the melt season. The outlet glaciers at Point C and D are no longer significantly tidewater. At Point B the outlet glacier is less than 0.5 km wide. The lake at the yellow arrows is 3 km long and 400 m wide. Some nunataks are coalescing with each other or the ice cap margin. The majority of the western margin of the ice cap has retreated 300-500 m. This retreat is surpassed at outlet glaciers by Point A and C. What is of greatest concern is the loss in thickness of over 1.5 per year on the highest portions of the ice cap, indicating no consistent accumulation zone. This results from the persistent loss of nearly all snowcover in the summer. This pattern of limited end of summer retained snowcover seen in most years since 2004, is a snow deficit that this ice cap cannot survive in our current warmer climate (Pelto, 2010). Way (2015) projects that that if the observed ice decline continues to AD 2100, the total area covered by ice at present will be reduced by more than 57%. Given the recent increases and lack of retained snowcover, suggests an even faster rate is likely.

1994 Landsat image

2000 Landsat image

2012 Landsat image

2014 Landsat image

Dexterity Ice Cap, Baffin Island

On March 10, 2013 By mspeltoIn Glacier Observations

At the south end of Dexterity Fjord on the northeast coast of Baffin Island is an unnamed icecap that I will refer to as Dexterity Icecap. Gardner et al (2012). Gardner et al 2011 and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years, the period of record. identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. Landsat images from 1990, 1994 and 2011 are used to assess the changes in this icecap. Red arrows are used to identify nunataks within the icecep, bedrock islands amidst the glacier. In 1990 and 1994 there are three evident nunataks. By 2011 there are six nunataks indicating this ice cap is thinning. In 2011 the ice cap has only 5-10% snowcover, the rest has melted away, not a good sign for an ice cap. There are a series of letters A-F on each image indicating particular locations. It is evident that the terminus has shrunk in width in particular in 2011 from the 1990’s. At Point B the glacier has receded from the edge of a small lake. At Point C a small ice cap has separated from its larger neighbor between the 1990’s and 2011. At Point D it is difficult to discern the terminus in the lake in 1990 and 1994. That the lake is open in 2011 and has numerous icebergs and the open water can absorb more heat from the sun, suggests that this terminus could suffer from enhanced melting and calving going forward. Point E represents a small tongue of ice that in the 1990’s extended to the top of gully, but by 2011 was gone. Point F indicates an ice cap that has a very tenuous connection to the Dexterity Ice Cap. It is the width of the ice cap that has diminished the most from 800-900 meters in the 1990’s to 500-600 m in 2011. The retreat of Dexterity Ice Cap is similar to that of Penny Ice Cap further south on Baffin Island and Devon Ice Cap further north in the Canadian Arctic. A paper out this past week concludes that there is an ongoing irreversible mass loss of glaciers in the Canadian Arctic Lenearts et al (2013).