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Storm Surges in the Canadian Beaufort Sea Steven M. Solomon 1 , Gavin Manson 1 , Donald Forbes 1 , Steven Kokelj 2 , Michael Pisaric 3 , Trevor Lantz 4 , Elisa J. Hart 5 , Humfrey Melling 6 Storm surge inundation extent and magnitude for a 2 m surge in the Hamlet of Tuktoyaktuk (based on LiDAR DEM) Erosion: Open-water season surges contribute to rapid erosion of unlithified, frozen coastal bluffs with as much as 10-15 m of erosion occurring during a single storm. In many locations surge-elevated waves directly impact coastal bluffs causing deep thermal notching followed by collapse of large blocks directly onto the beach. Flooding: Where elevations are lower, extensive flooding occurs causing problems for both permanent and seasonal communities and for industrial activities (e.g. hydrocarbon exploration). The Associated Press Analysis of Data and Predictions: Storm surge chronologies are challenging to construct due to a lack of observations and the limited time span covered by the instrumental records. In the Canadian Beaufort Sea, official coastal meteorological and water level records extend back to the early 1960s, although the records are far from complete with very few reporting stations. Probabilities of exceedance were calculated using a “peaks over threshold” method. Return periods for peak wind speeds and water levels at Tuktoyaktuk are predicted. Water levels exceeding 2 metres relative to chart datum and winds in excess of 90 km h -1 are shown to be a rare occurrence. Hudson Bay Company Employee’s Description of 1944 storm at Tuktoyaktuk By 4 p.m. we noticed the water was receding and congratulated ourselves on only losing empty drums...and everyone...went in for coffee. Just as King and I were having ours I looked out of the window and to my amazement saw the Transport office move, move again and go sailing round the warehouse on an even keel past the wharf and go sailing over to the island. ...as Charlie Smith said to me, when the office came sailing round the warehouse, he expected the stove pipe to give a cheery whistle. As soon as the warehouse hit the island it just broke up into a hundred pieces. By then the water had flooded all the lot, the sand spit and right around the house. You can’t imagine the scene, Diesel oil drums, gas drums, coal oil drums, full and empty crashing around and floating away, dogs, board walks, warf and lumber, all going, water pouring into store and warehouse and into the house, the two of us trying to do a hundred jobs at once and getting desperate....the water was 12 inches deep in the warehouse, store and dwelling house. We had an inch rope round the house, between house and store the water was almost waist deep. Time-time plot shows the seasonality of water levels and the fragmentary nature of the Tuktoyaktuk water level record. An unusual event in 1999 led to the salinization of 200 km 2 of highly productive waterfowl habitat in the Mackenzie Delta. Impacted areas are easily discernable on Landsat imagery. 0 10 20 30 40 50 60 70 80 90 100 29-Dec- 04 03-Jan- 05 08-Jan- 05 13-Jan- 05 18-Jan- 05 23-Jan- 05 28-Jan- 05 02-Feb- 05 07-Feb- 05 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Wind Spd (km/h) Tuk_WL (m) Open Water Season Water Levels - greater than 1 m 0 50 100 150 200 250 300 350 1-Jun-70 31-May-75 29-May-80 28-May-85 27-May-90 26-May-95 24-May-00 23-May-05 22-May-10 Water level (cm) 75 kilometres 0 37 .5 Winter surges: Winter-season surges also occur, despite complete ice cover, causing pressure ridge development, ice scour, flooding and breakup of ice roads and potential erosion of ice-constrained channel mouths. Ivu, or ice push, associated with winter surges can extend onto land with associated risk to human life and infrastructure. The graph on the left shows water levels from Tuktoyaktuk for a surge in January 2005 that was caused by winds exceeding 80 km h -1 (> 20 m s -1 ). The image on the right shows the clean-up of an Ivu event at Barrow, Alaska (January 2006) that snapped telephone poles and blocked roads. SAMPLE WORKSHEET FROM BAILLIE ISLAND HUDSON BAY COMPANY POST JOURNALS Date Day Post Wnd Dir Wnd Desc W SPD Dur Sev Tide Description 31/7/28 214 BI E B 45.0 21 42.5 wind still blowing east and heavy on seas running (2400-2100) 12/8/28 226 BI SW- NW S 40.2 13 21 H strong SW wind morning, afternoon developed into strong NW squally. Heavy seas in bay. High water in afternoon. (0800- 2100) 16/8/28 230 BI NW S 40.2 13 21 H strong - heavy flooding. The sand spit was completely flooded today. The water was right up to the store and some tins of gasoline etc. were carried out to sea. Billy Bankslands schooner North Star and Peter Lopezs scow blown from moorings at height of gale and washed right over sand spit - last seen drifting with the current eastward. Schooners belonging to David and Sakitok were also blown on to the sandspit. This is the worst gale known since 1919, and every tent was washed out and only the houses on the sand spit remained free from water inside. Toward evening gale abated somewhat but water still very high. (08:00-12:00) Information from church records, ship’s logs and trading company reports augment the instrumental record from anemometers and tide gauges. Numerical models allow us to fill in missing data and assess the quality of anecdotal reports. The upper figure shows storm surges > 1 m based on modeling using ADCIRC and forced by hindcast winds from 1970-2009. The lower figure shows the spatial distribution of water level during the 1999 storm event. 1 Natural Resources Canada, 2 Indian and Northern Affairs Canada; 3 Carleton University; 4 University of Victoria; 5 Cochrane, Alberta; 6 Fisheries and Oceans Canada Introduction: Storm surges forming over the extensive shallow shelf of the eastern Beaufort Sea can have significant impacts on human activities and natural ecosystems. The Canadian sector of the region includes the Mackenzie River Delta and a rich and diverse ecosystem. The area supports a vibrant subsistence economy as well as oil and gas exploration, tourism and other industrial uses. This presentation describes aspects of the storm surge climatology and its impacts. The Future Relative sea level in the region is rising due to a combination of local and regional subsidence and sea level rise. Sea ice duration is expected to decrease as the Arctic warms and eustatic sea level rise is expected to accelerate. Therefore, total water levels associated with storm surges are expected to increase. The potential trajectory for frequency and duration of storms is not well constrained by climate model projections. Present variability is too large and the record too short to detect trends, but even if storminess remains unchanged the exposure to damaging surges is likely to increase due to changing sea ice conditions and rising sea level. The map on the right illustrates the very low coastal gradient and extensive coastal lowlands (< 2 m) associated with the Mackenzie delta region. 1970 1993 1999
1

Storm Surges in the Canadian Beaufort Sea...Storm Surges in the Canadian Beaufort Sea Steven M. Solomon 1, Gavin Manson , Donald Forbes , Steven Kokelj2, Michael Pisaric3, Trevor Lantz4,

Mar 17, 2020

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Page 1: Storm Surges in the Canadian Beaufort Sea...Storm Surges in the Canadian Beaufort Sea Steven M. Solomon 1, Gavin Manson , Donald Forbes , Steven Kokelj2, Michael Pisaric3, Trevor Lantz4,

Storm Surges in the Canadian Beaufort SeaSteven M. Solomon1, Gavin Manson1, Donald Forbes1, Steven Kokelj2, Michael Pisaric3, Trevor Lantz4, Elisa J. Hart5, Humfrey Melling6

Storm surge inundation extent and magnitude for a 2 m surge in the Hamlet of Tuktoyaktuk(based on LiDAR DEM)

Erosion: Open-water season surges contribute to rapid erosion of unlithified, frozen coastal bluffs with as much as 10-15 m of erosion occurring during a single storm. In many locations surge-elevated waves directly impact coastal bluffs causing deep thermal notching followed by collapse of large blocks directly onto the beach.

Flooding: Where elevations are lower, extensive flooding occurs causing problems for both permanent and seasonal communities and for industrial activities (e.g. hydrocarbon exploration).

The Associated Press

Analysis of Data and Predictions: Storm surge chronologies are challenging to construct due to a lack of observations and the limited time span covered by the instrumental records. In the Canadian Beaufort Sea, official coastal meteorological and water level records extend back to the early 1960s, although the records are far from complete with very few reporting stations.

Probabilities of exceedancewere calculated using a “peaks over threshold”method. Return periods for peak wind speeds and water levels at Tuktoyaktukare predicted. Water levels exceeding 2 metres relative to chart datum and winds in excess of 90 km h-1 are shown to be a rare occurrence.

Hudson Bay Company Employee’s Description of 1944 storm at TuktoyaktukBy 4 p.m. we noticed the water was receding and congratulated ourselves on only losing empty drums...and everyone...went in for coffee.

Just as King and I were having ours I looked out of the window and to my amazement saw the Transport office move, move again and go sailing round the warehouse on an even keel past the wharf and go sailing over to the island. ...as Charlie Smith said to me, when the office came sailing round the warehouse, he expected the stove pipe to give a cheery whistle. As soon as the warehouse hit the island it just broke up into a hundred pieces. By then the water had flooded all the lot, the sand spit and right around the house. You can’t imagine the scene, Diesel oil drums, gas drums, coal oil drums, full and empty crashing around and floating away, dogs, board walks, warf and lumber, all going, water pouring into store and warehouse and into the house, the two of us trying to do a hundred jobs at once and getting desperate....the water was 12 inches deep in the warehouse, store and dwelling house. We had an inch rope round the house, between house and store the water was almost waist deep.

Time-time plot shows the seasonality of water levels and the fragmentary nature of the Tuktoyaktuk water level record.

An unusual event in 1999 led to the salinization of 200 km2 of highly productive waterfowl habitat in the Mackenzie Delta. Impacted areas are easily discernable on Landsat imagery.

0

10

20

30

40

50

60

70

80

90

100

29-Dec-04

03-Jan-05

08-Jan-05

13-Jan-05

18-Jan-05

23-Jan-05

28-Jan-05

02-Feb-05

07-Feb-05

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Wind Spd (km/h) Tuk_WL (m)

Open Water Season Water Levels - greater than 1 m

0

50

100

150

200

250

300

350

1-Jun-7031-May-75

29-May-8028-May-85

27-May-9026-May-95

24-May-0023-May-05

22-May-10

Wat

er le

vel (

cm)

75

kilometres

0 37.5

2.8910

2.0000

1.5000

1.7500

1.2500

0.3490

0.5000

1.0000

Winter surges: Winter-season surges also occur, despite complete ice cover, causing pressure ridge development, ice scour, flooding and breakup of ice roads and potential erosion of ice-constrained channel mouths. Ivu, or ice push, associated with winter surges can extend onto land with associated risk to human life and infrastructure.

The graph on the left shows water levels from Tuktoyaktuk for a surge in January 2005 that was caused by winds exceeding 80 km h-1 (> 20 m s-1). The image on the right shows the clean-up of an Ivuevent at Barrow, Alaska (January 2006) that snapped telephone poles and blocked roads.

SAMPLE WORKSHEET FROM BAILLIE ISLAND HUDSON BAY COMPANY POST JOURNALS Date

Day

Post

Wnd Dir

Wnd Desc

W SPD

Dur

Sev

Tide

Description

31/7/28

214

BI

E

B

45.0

21

42.5

wind still blowing east and heavy on seas running (2400-2100)

12/8/28

226

BI

SW-NW

S

40.2

13

21

H

strong SW wind morning, afternoon developed into strong NW squally. Heavy seas in bay. High water in afternoon. (0800-2100)

16/8/28

230

BI

NW

S

40.2

13

21

H

strong - heavy flooding. The sand spit was completely flooded today. The water was right up to the store and some tins of gasoline etc. were carried out to sea. Billy Banksland’s schooner North Star and Peter Lopez’s scow blown from moorings at height of gale and washed right over sand spit - last seen drifting with the current eastward. Schooners belonging to David and Sakitok were also blown on to the sandspit. This is the worst gale known since 1919, and every tent was washed out and only the houses on the sand spit remained free from water inside. Toward evening gale abated somewhat but water still very high. (08:00-12:00)

Information from church records, ship’s logs and trading company reports augment the instrumental record from anemometers and tide gauges.

Numerical models allow us to fill in missing data and assess the quality of anecdotal reports. The upper figure shows storm surges > 1 m based on modeling using ADCIRC and forced by hindcast winds from 1970-2009. The lower figure shows the spatial distribution of water level during the 1999 storm event.

1Natural Resources Canada, 2Indian and Northern Affairs Canada; 3Carleton University; 4University of Victoria; 5Cochrane, Alberta; 6Fisheries and Oceans Canada

Introduction: Storm surges forming over the extensive shallow shelf of the eastern Beaufort Sea can have significant impacts on human activities and natural ecosystems. The Canadian sector of the region includes the Mackenzie River Delta and a rich and diverse ecosystem. The area supports a vibrant subsistence economy as well as oil and gas exploration, tourism and other industrial uses. This presentation describes aspects of the storm surge climatology and its impacts.

The FutureRelative sea level in the region is rising due to a combination of local and regional subsidence and sea level rise. Sea ice duration is expected to decrease as the Arctic warms and eustatic sea level rise is expected to accelerate. Therefore, total water levels associated with storm surges are expected to increase. The potential trajectory for frequency and duration of storms is not well constrained by climate model projections. Present variability is too large and the record too short to detect trends, but even if storminess remains unchanged the exposure to damaging surges is likely to increase due to changing sea ice conditions and rising sea level.

The map on the right illustrates the very low coastal gradient and extensive coastal lowlands (< 2 m) associated with the Mackenzie delta region.

1970

1993 19

99