Coastal Classification of Nunavik & Dynamics of the Arctic/Subarctic coastal environments ·...

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Antoine Boisson Centre d’études nordiques Université Laval, Québec, Canada [email protected] Coastal Classification of Nunavik & Dynamics of the Arctic/Subarctic coastal environments Michel Allard [email protected]

Transcript of Coastal Classification of Nunavik & Dynamics of the Arctic/Subarctic coastal environments ·...

Antoine BoissonCentre d’études nordiques

Université Laval, Québec, Canada

[email protected]

Coastal Classification of Nunavik &

Dynamics of the Arctic/Subarctic coastal environments

Michel [email protected]

Background

≈ 10,000 km (CanVec)

4 % of Canada’s coastline

Nunavik’s coastline

Eastern coast of Hudson Bay

Southern coast of Hudson Strait

Coast of Ungava Bay

Inhabited by 14 Inuit communities & 1 Cree community

Context of global warming

Permafrost thaw, hydrodynamic changes, etc.

Context of high economical potential

Mines, port infrastructures

Emerging coasts; Sea level fall

Hydrodynamic conditions

HB: wave-dominated

HS-UB: tide-dominated

Sea ice is a defining seasonal feature of this coastline.

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Post-glacial marine transgression (D’Iberville)

Post-glacial marine transgression (Tyrrell)

Marine limit (m)

Vincent, 1989

Ungava

Bay

Hudson Bay

James

Bay

Nunavik is influenced by ongoing glacio-isostatic

uplift, with current emergence rates of about 5 to

13 mm/yr, counterbalancing the rising relative sea-

level in the context of climate change.

Background

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James et al., 2014

Kuujjuaq, QC

0.8 mm/yr

Inuvik, NT Iqaluit, NUInukjuak, QCKuujjuarapik, QC

1.37 mm/yr 1.05 mm/yr

Where the land is rising rapidly, due to postglacial

rebound, sea level is projected to continue to fall.

The total expected sea level change over the period 1995-2100 is

more than 1 m for Kuujjuarapik and Inukjuak; 80 cm for Kuujjuaq.

Background

Post-glacial marine transgression (D’Iberville)

Post-glacial marine transgression (Tyrrell)

Marine limit (m)

Vincent, 1989

Ungava

Bay

Hudson Bay

James

Bay

Main questions

What are the different types of coast?

Are they in erosion? In progradation? Why?

What are the coastal hazards? & which communities are the most vulnerable?

Objective

To collect audio descriptions, photos and videos of the coastal zone in order to help to

interpret the shoreline type and create a digital shoreline database.

Material

Bell Helicopter 206 Long Ranger

JVC Pro GY-HM100U video camera

Nikon D7100 camera

VMS 333 (Video Mapping System)

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VMS-333

GPS

Microphone

Camera

VMS-333

battery

eSPACE: emergency Spatial Pre-SCAT for Arctic Coastal Ecosystems.

SCAT: Shoreline Cleanup Assessment Technique.

In 2009, Environment Canada initiated a national project in the Canadian Arctic to improve emergency

preparedness and response related to potential oil spills and their impact on coastal ecosystems.

Geotagged shoreline videography and photography by helicopter

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Wynja et al., 2015

Geotagged shoreline videography and photography by helicopter

Flight characteristics

Spatially referenced: video with x, y coordinates

Low altitude: around 90-120 m

Close to shore: 100-150 m

Oblique video: 45°

Web Map

National Wildlife Research Center

Carleton University

Environment Canada

Geotagged shoreline videography and photography by helicopter

45h of video recordings & 37,000 photos (7,200 km)

Wynja et al., 2015

Coastal segmentation and classification

Shoreline database

Mapping procedure is based on

shoreline segmentation defined by

the eSPACE project.

Descriptive attributes (substrate,

slope, shore type, exposure) are

input into a custom data entry

form for each shore segment to

describe both the alongshore

segment and the cross-shore

morphology (intertidal, supratidal

and backshore zones).

SCAT: Shoreline Cleanup Assessment Technique.

Coastal segmentation and classification

Boisson et al., 2015

Hudson Strait

Mixed & Coarse

Sediment Tidal Flat

++++

Bedrock Cliff/Vertical ++++

Bedrock Sloping/Ramp ++++

Boulder Beach ++++

Pebble/Cobble Beach +++

Mixed Sediment Beach ++

Sand Beach +

Sand Tidal Flat +

Mud Tidal Flat – Marsh +

Bedrock Platform +

Man-Made +

Ungava Bay

Bedrock Sloping/Ramp ++++

Mixed & Coarse

Sediment Tidal Flat

++++

Boulder Beach ++++

Mud Tidal Flat – Marsh ++++

Bedrock Platform +++

Sand Tidal Flat ++

Mixed Sediment Beach ++

Bedrock Cliff/Vertical ++

Pebble/Cobble Beach ++

Man-Made +

Sand Beach +

Hudson Bay

Pebble/Cobble Beach ++++

Bedrock Sloping/Ramp ++++

Bedrock Platform +++

Boulder Beach +++

Mixed Sediment Beach +++

Sand Beach ++

Mixed & Coarse

Sediment Tidal Flat

++

Mud Tidal Flat – Marsh +

Bedrock Cliff/Vertical +

Sand Tidal Flat +

Man-Made +

Coastal segmentation and classification

Rocky coasts

Cliff near Cape Wolstenholme

Rocky coasts

Cuestas – Manitounuk Strait

Rocky coasts

Rocky platform at the mouth of the Koksoak River, Ungava Bay

Rocky coasts

Key points

Mosaic of rocky coasts.

Continually affected by frost-weathering

processes since the withdrawal of the

Laurentide Ice Sheet and following

emergence from the postglacial sea.

No coastal retreat, except cliff stretches.

Fjords and talus cones between Ivujivik and Salluit, Hudson Strait

Mosaic of beaches

Pocket sand beach 100 km north of Umiujaq, southeastern Hudson Bay

Mosaic of beaches

Tombolo 100 km north of Umiujaq, southeastern Hudson Bay

Mosaic of beaches

Raised beaches 50 km west of Quaqtaq, Hudson Strait

Mosaic of beaches

Key points

A general progradation of sedimentary environments (beaches, sand spits, tombolos, tidal flats, deltas).

Few eroded coastlines.

Development of dunes, wetlands, lacustrine environments.

Raised beaches.

Emerging De Geer moraines between Akulivik and Ivujivik, Kovik Bay

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Components of a De Geer

moraine (DGM) coastline

along the Kovik River valley.

A prograding coast.

A “gridded pattern” of De Geer

moraines, drumlinoid ridges,

eskers, and inter-moraine

depressions structures the

coastal system into short

beaches and spits, tombolos,

small bays and pocket coastal

marshes.

De Geer moraine

coastlines

Tidal flats

Muddy tidal flats between Kuujjuaq and Kangiqsualujjuaq, Ungava Bay

Tidal flats

Muddy and rocky tidal flats between Kuujjuaq and Kangiqsualujjuaq, Ungava Bay

Tidal flats

Key points

Mostly in Ungava Bay

A general progradation

Boulder-strewn tidal flats, 7 km northwest of Tasiujaq, Leaf Basin, Ungava Bay

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Permafrost coasts

An eroding permafrost coastline with ice-wedge polygons, 10 km southwest of Salluit, Sugluk Fjord

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Permafrost coasts

An eroding permafrost coastline with a micro-cliff and thermokarst lakes, 55 km north of Puvirnituq

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Permafrost coasts

Key points

Few eroded permafrost coastlines.

Thermo-erosion gullies, thermokarst lakes.

Aggradation of permafrost in intertidal and

supratidal zones.

Eroding permafrost bluff on the bank of permafrost plateau in Manitounuk Strait, 40 km northeast of Kuujjuarapik

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Storm surge flooding risk

Storm surge

Temporary difference between theexpected water level and that experiencedat a location due to extreme meteorologicalconditions such as low atmosphericpressure and strong onshore winds.

Positive storm surges (surcotes) will be

more numerous and stronger on all the

coasts of Nunavik (Massé and Gallant,

2016).

Negative storm surges (decotes) will be

more numerous and/or stronger on the

coast of HB, but fewer on the coasts of HS

and UB (Massé and Gallant, 2016).

Storm surge flooding in Salluit

NOAA

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Aubé Michaud et al., 2017

Wind resultant

Storm surge flooding risk

Inukjuak

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Aubé Michaud et al., 2017The risk of storm surge flooding is very high. Five newly built houses

could be flooded in the case of a positive storm surge of 1.2 m.

Akulivik

Storm surge flooding risk

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Mic

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d e

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torm

su

rge f

loo

din

g r

isk

Quaqtaq

IvujivikPuvirnituq

Kangiqsujuaq

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In the context of climate change, this coastal

hazard should be better understood and

managed in the next few years.

Makeshift seawall in Salluit

Eroded coastline in Umiujaq

Storm surge flooding risk

33Clerc et al., 2012

Ice pushes

Bleau (2012)

Lateral pressure caused by the

extension of ice on bays, straits

and lakes. Sea ice is forced by

waves and strong onshore

winds to lie upon the coast.

Once on the banks, the ice

pushes and scours beach

sediments to form bulges below

and above the high tide zone.

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Coastal sensitivity

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The erosion and leveling of emerging rocky coasts; No coastal retreat, except

cliffs.

The erosion and the reworking of sediments of emerging landforms such as De

Geer moraines and drumlinoid ridges;

The progradation of sedimentary environments such as beaches, dunes (nebkhas,

embryo dunes), spits, tidal flats;

The aggradation of permafrost in intertidal and supratidal zones; Few eroded

permafrost coasts;

Some coastal risks.

Key points

Merci – Thank you – Nakurmimarialuk

Questions?

MFFP (Ministère des Forêts, de la Faune et des Parcs)

ArcticNet

Centre d’études nordiques (CEN): S. Aubé Michaud, A. Chiasson, J. Roger, D. Sarrazin…

Environment Canada eSPACE team: S. Laforest, J. Pasher, V. Wynja…

Acknowledgements