The Arctic Coastal Dynamics Database: A New Classification
Scheme and Statistics on Arctic Permafrost Coastlines
Hugues Lantuit & Pier Paul Overduin & Nicole Couture & Sebastian Wetterich &
Felix Aré & David Atkinson & Jerry Brown & Georgy Cherkashov & Dmitry Drozdov &
Donald Lawrence Forbes & Allison Graves-Gaylord & Mikhail Grigoriev &
Hans-Wolfgang Hubberten & James Jordan & Torre Jorgenson &
Rune Strand Ødegård & Stanislav Ogorodov & Wayne H. Pollard & Volker Rachold &
Sergey Sedenko & Steve Solomon & Frits Steenhuisen & Irina Streletskaya &
Alexander Vasiliev
Received: 10 March 2010 / Revised: 6 December 2010 /Accepted: 7 December 2010
#
Coastal and Estuarine Research Federation 2011
Abstract Arctic permafrost coasts are sensitive to chang-
ing climate. The lengthening open water season and the
increasing open water area are likely to induce greater
erosion and threaten community and industry infrastructure
as well as dramatically change nutrient pathways in the
near-shore zone. The shallow, mediterranean Arctic Ocean
is likely to be strongly affected by changes in currently
poorly observed arctic coastal dynamics. We present a
geomorphological classification scheme for the arctic coast,
with 101,447 km of coastline in 1,315 segments. The
average rate of erosion for the arctic coast is 0.5 m year
−1
with high local and regional variability. Highest rates are
observed in the Laptev, East Siberian, and Beaufort Seas.
Strong spatial variability in associated database bluff
height, ground carbon and ice content, and coastline
movement highlights the need to estimate the relative
importance of shifting coastal fluxes to the Arctic Ocean
at multiple spatial scales.
Keywords Arctic
.
Coast
.
Permafrost
.
Erosion
.
Carbon
cycle
Introduction
Arctic coasts are likely to become one of the most
impacted environments on Earth under cha n ging climate
conditions. Under most scenarios, the Arctic is predicted
to experience the strongest air and sea temperature
increase at the Earth’s surface (Kattsov and K ällén
2005). As a result, the lengthening open water season
and the increasing open water area, due to the decline of
H. Lantuit
:
P. P. Overduin
:
S. Wetterich
:
H.-W. Hubberten
Alfred Wegener Institute for Polar and Marine Research,
Research Section Potsdam,
Telgrafenberg A43,
14473 Potsdam, Germany
H. Lantuit (*)
:
J. Brown
International Permafrost Association,
Telegrafenberg A43,
14473 Potsdam, Germany
e-mail: hugues.lantuit@awi.de
N. Couture
Northern Canada Division, Geological Survey of Canada,
601 Booth Street,
Ottawa, ON K1A 0E8, Canada
F. Aré
St. Petersburg State University,
St. Petersburg, Russia
D. Atkinson
International Arctic Research Center,
Fairbanks, AK, USA
G. Cherkashov
VNIIOkeangeologia,
St. Petersburg, Russia
D. Drozdov
Earth Cryosphere Institute, RAS,
Moscow, Russia
D. L. Forbes
:
S. Solomon
Geological Survey of Canada,
Dartmouth, NS, Canada
A. Graves-Gaylord
Nunatech Technologies,
Anchorage, AK, USA
Estuaries and Coasts
DOI 10.1007/s12237-010-9362-6
sea ice extent, will induce changes to the length of fetch
and allow s tor ms t o affect the coasts l ater in the fall season
(Anisimov et al. 2007;Atkinson2005). These storms are
thought to threa ten communi ty and industry infrastructure
as well as to dramatically change sediment and nutrient
pathways in the near-shore zone (Dunton and Cooper
2005). Unfortunately, Arctic coastal dynamics remain
largely understudied and seldom modeled, which puts
current adaptat ion and mitigation strategies in northern
communities into jeopardy. A thorough systematic inves-
tigation of the coast at t he circ um –arctic scale is needed to
better understand the processes that act upon it. Only then
will it be possible to develop pre d ictiv e models of coa stal
evolution.
Coastal erosion in the Arctic differs from its counterpart
in temperate regions due to the short open-water season (3–
4 months, from about Ju ne to mid-Oc tober ) and th e
presence of ice in the marine and terrestrial environments
(Fig. 1). Storms, which are often the main driver of erosion,
occur throughout the year but their impact is limited due to
the presence of sea ice cover during the fall, winter and
spring (Atkinson 2005). Even during the summer period,
chunks of sea ice in various quantities and sizes can impede
the development of waves in the shore zone. Coastal retreat
rates are highly variable both spatially and temporally, in
relation to variations in the lithology, cryology, and
geomorphology of coastal cliffs (Jones et al. 2008; Lantuit
and Pollard 2008; Solomon 2005). Temporal variability is
related to storminess, thermal conditions, and sea-ice
conditions in the coastal zone (Solomon et al. 1994 ). Ice
in the terrestr ial part of the permafrost coastal system
occurs as ground ice. It is present in the subaerial part of the
shore profile, but also be neath the water colu mn, as
submarine ground ice (Mackay 1972;Racholdetal.
2007). The presence of terrestrial ground ice allows
abrasion to proceed faster; a process termed “thermal
abrasion” (Aré 1988) which encompasses the combined
kinetic action of waves and thawing of the permafrost.
Upon melting, it enhances coastal zone susceptibility to
erosion, (Héquette and Barnes 1990; Kobayashi et al.
1999), especially when present as massive ice in coastal
cliffs, or through the occurrence of large thermokarst
features in the coastal zone (Lantuit and Pollard 2005;
2008)
The coast, whether in temperate or polar regions, is a
complex and diverse environment, at a number of spatial
scales. This complexity is di fficu lt to capture with a
systematic or rigid compa rtmentalizing approach. Never-
theless, classifications, whether hypothesis-driven or de-
scriptive, have been a major instrum ent in the pursuit of
scientific knowledge, helping to delineate natural systems
and achieve economy of memory (Sokal 1974). Coastal
scientists have not refrained from proceeding with formal
descriptions of the structure of coastal components. As
early as the nineteenth century, (notwithstanding traditional
descriptions of coastal processes by indigenous people),
geologists attempted to describe coastal landforms and to
explain their origin and development. Classification
schemes were rapidly devised, mostly based on a division
of the coast into areas of similar geology and environment.
A review of coastal classification efforts and history is
Fig. 1 Physiographic setting and processes active on Arctic perma-
frost coasts. Ice, in the form of sea ice or ground ice in permafrost,
induces a response to environmental forcing that differs from that
observed on temperate coasts
M. Grigoriev
:
S. Sedenko
Melnikov Permafrost Institute,
Yakutsk, Russia
J. Jordan
Antioch University New England,
Keene, NH, USA
T. Jorgenson
ABR Inc,
Fairbanks, AK, USA
R. S. Ødegård
Gjovik College,
Gjovik, Norway
S. Ogorodov
:
I. Streletskaya
:
A. Vasiliev
Moscow State University,
Moscow, Russia
W. H. Pollard
McGill University,
Montréal, QC, Canada
V. Rachold
International Arctic Science Committee,
Potsdam, Germany
F. Steenhuisen
Arctic Centre, University of Groningen,
Groningen, The Netherlands
Estuaries and Coasts
provided by Finkl (2004). Existing coastal classifications
share a common deficiency in their description of arctic
coasts, especially those affected by the presence of
permafrost. Typically, they classify the arctic coastal zone
as one single category. We suggest that this approach does
not do justice to the wide variety of coastal landforms and
processes observed at the land–sea interface in the Arctic.
Historically, the lack of a classification scheme for arctic
coasts can be explained by the late exploration of polar
regions, by their remoteness, and by the low population
density of the arctic coastal zone, limiting the economic
relevance of studies in the north. The widely used
classification of the coasts by Shepard (1948) divides
shorelines into two categories, prim ary (shaped by non-
marine processes) and secondary (shaped b y marine
processes), but does not include sea ice in the coastal zone
or the role of permafrost in thermal–mechanical erosion.
Classifications based on the division between submergent
and emergent coasts, such as that by Valentin (1952), also
fail to mention permafrost and sea ice despite the important
role of isostasy in determining geomorphol ogy in the Arctic
(Whitehouse et al. 2007). Classifications of the arctic coast
exist at the national level (e.g., for Russia, Drozdov et al.
2005), but not yet at the circum-arctic scale.
Arctic permafrost coastlines represent approximately
34% of the world’s coastlines and are affected by the
presence of permafrost and/or seasonal sea ice cover,
resulting in unique conditions, landforms, and processes.
These e nvironments are undergoing tremendous change
that results in redefined societal and environmental
frameworks. Traditional use of the coast by Inuit
communities in Canada and Alaska is threatened by the
disappearance of sea ice (Huntington and Fox 2005). The
subsequent opening of the northern sea route in Russia’s
waters and of the Northwest Passage in the Canadian
Archipelago w ill call upon local, regional, and interna-
tional stakeholders to define new strategies for the use and
protection of the coast (Matushenko 2000). The lack of a
baseline dataset that accurately captures the physical state
of the coast and includes the specificity of the Arctic
hinders the development of such strategies. The urgency to
develop such a dataset, based on a classification method
specifically devised for the Arctic, is genuine and palpable.
This paper presents a classification scheme by the Arctic
Coastal Dynamics (ACD) project, initiated by the Interna-
tional Permafrost Association in 1999 (Brown and Solomon
2000) and carried out on a cooperative basis starting in
2000 with the International Arctic Science Committee
(Rachold et al. 2002, 2003 , 2005; Rachold and Cherkasov
2004), with specific aims of establishing the rates and
magnitudes of erosion and accumulation of arctic coasts
and of creating an arctic coastal classification in digital
form. ACD is also an affiliated project with the Land–
Oceans Interactions in the Coastal Zone project, which in
turn is part of both the International Geosphere-Biosphere
Programme, and the International H uman Dimension
Programme.
Methods
Segmentation of the Coast
The central objective of the ACD classification is to assess
the sensitivity and erosion potential of arctic coasts. The
classification was the refore conceived as a framework
broad enough to encompass existing classification schemes,
while capturing fundamental information for the assessment
of climate change impacts and coast al processes in relation
to the specificity of arctic coast s.
The first step in establishing this classification consisted
in segmenting the arctic coast in a consistent and systematic
manner. Here, we apply a constrained definition of the
Arctic, limiting our study area to the coasts bordering the
Arctic Basin and excluding much of the Canadian Arctic
Archipelago and northern Québec, southern Greenland,
Iceland, the Faeroe Islands, Scandinavia, and southern
Alaska (Fig. 2). Much of the Canadian Archipelago,
Greenland, and the Bering Sea are excluded for three main
reasons. First, the tacit objective of this classification is to
focus on sediment fluxes from arctic coasts to the enclosed
Arctic Ocean and not to the Pacific, which excluded the
Bering Sea. Second, development of this classification
relied on existing data on coastal geomorphology, which is
scarce for the Canadian Archipelago and Greenland. Third,
most of the coasts of the Canadian Archipelago and
Greenland are consolidated and uplifting, with little to no
coastal erosion, which greatly limits the impact of erosion
for these coasts on the overall sediment budget.
To conform to the objective of the project, the
compartmentalization of the coast was primarily geomor-
phological in nature, so that it emphasizes erosion and
changes to the coastal tract. The basic concept underlying
the segmentation, freely adapted from Howes et al. (
1994),
is that the shore zone can be subdivided and described in
terms of a systematic collection of physical entities. In
short, a coastline can be subdivided into smaller segments,
and the features of each segment described and recorded.
The method first segments the coastline into alongshore
units that exhibit homogeneous forms and material types,
then subdivides these segments into across-shore compo-
nents, and describes them.
To proceed with the first step of the segmentation, the
following characteristics were considered: (1) the shape or
form of the terrestrial part of the coastal tract, (2) the marine
processes acting upon the coast, (3) the shape or the form of
Estuaries and Coasts
the subaqueous part of the coastal tract, and (4) the
lithofacies of the materials constituting the coastal tract.
The coastal tract we use follows the definition of Cowell et
al. (2003). The segmentation of the shoreline was defin ed
by members of the ACD project and the Arctic Circumpolar
Coastal Observatory Network, based on field investiga-
tions, digital and paper products, as well as on personal
knowledge. Details on the segmentation procedure are
given in reports of the ACD workshops in Rachold and
Cherkashov (2004), Rachold et al. (2002; 2003; 2005), and
Overduin and Couture ( 2008). The Arctic was organized
into 10 sectors around the seas of the Arctic Ocean (Fig. 2,
Table 1). To ensure consistency in the segmentation
procedure, cross- review segmentations and independent
oversight in the process were organized over the course of
the ACD project (Lantuit et al. 2006; Overduin and Couture
Fig. 2 The Arctic region, as defined by the Arctic Monitoring and Assessment Program (AMAP), with the extent of the classification featured in
this paper and the Arctic ocean sea sectors used to divide the coastline. Average sea ice extent for September is also shown
Estuaries and Coasts
2006, 2008; Overduin et al. 2007). The segments were then
organized in an ISO-compliant geodatabase and individu-
ally referenced according to a predefined template. The
geospatial processing and referencing process are described
in detail by Lantuit et al. (2010a).
Cross-shore Characterization
The second step consisted in characterizing the cross-shore
components of each segment. Each along-shore unit was
divided into four cross-shore units which were described in
terms of their shape (or morphology) and their material
type. The cross-shore units were identified as the onshore,
backshore, frontshore, and offshore (Fig. 3). These desig-
nations are defined in Appendix A and are specific to this
classification, although largely inspired by existing schemes
(e.g., Komar 1998; Cowell et al. 2003). The specific shape
of the shoreface in arctic settings, as highlighted by Are et
al. (2008) and Are and Reimnitz (2008), does not preclude
the use of these generic terms in describing its morphology.
The term “backshore” was defined to refer primarily to the
area landward of the active beach, whereas the term
“frontshore” was defined to include both the foreshore
and the surf zone. The “onshore” category referred to the
local and regional setting adjacent to those zones which are
immediately affected by marine processes. The offshore
zone was defined as the zone extend ing from the lower end
of the frontshore zone to the 100 m isobath. The offshore
zone, like the onshore zone, provided context for the
classification of the coastal region, and was described in
terms of its steepness and relief characteristics (i.e., slope)
using resources such as topographic maps, bathym etric
maps and digital terrain models. Onshore reli ef was
expressed as distances to topographical contours. Offshore,
the relief was expressed as distances to the 2, 5, 10, and
100-m isobaths. The backshore and front shore zones were
labeled using categories that described the shape of those
zones in genetically neutral, geome trically defined terms.
The range of morphological terms used to describe each of
these zones is listed in Appendix A and included forms
such as ridge d or terraced frontshore deposits, beaches, or
cliffs.
For all cross-shore zones, the material was specified as
shown in Appendix A. Unlithified and lithified coastal
segments were differentiated in the process. For unlithified
coasts, a detailed account of the grain size was provided,
encompassing standard grain-size categories (gravel, sand, silt,
clay). Lithified coastal sections were characterized by the
geological and mineralogical nature of the exposed bedrock.
For the purpose of quantifying sediment and organic carbon
release to the near-shore zone, erosion and redeposition in the
frontshore and offsho re zone were considered to be transient
phenomena; and detailed characterization of soil geotechnical
and geocryological properties focused only on the backshore
zone (e.g., bulk density and volumetric ground ice contents).
Fig. 3 The cross-shore units
used to describe the coastal
zone in the classification.
Adapted from the coastal tract
concept from Cowell et al.
(2003)
Table 1 Divisions of the Arctic coast used in this paper based upon
Arctic seas
Sea name Length (km) Percentage of total
coastline length (%)
Russian Chuckchi Sea 2,736 2.7
American Chuckchi Sea 4,662 4.6
American Beaufort Sea 3,376 3.3
Canadian Beaufort Sea 5,672 5.6
Greenland Sea and Canadian
Archipelago
4,656 4.6
Svalbard 8,782 8.7
Barents Sea 17,965 17.7
Kara Sea 25,959 25.6
Laptev Sea 16,927 16.7
East Siberian Sea 8,942 8.8
Total 101,447 100.0
Coastline lengths are based on the World Vector Shoreline (Soluri and
Woodson, 1990)
Estuaries and Coasts
