Introduction

Fjords occur along many high-latitude coastlines today including those of Alaska, Antarctica (the Peninsula and along mainland coasts), Canada (British Columbia, Labrador, Newfoundland, Quebec, Baffin Island and Queen Elizabeth Islands), Chile, Greenland, Iceland, New Zealand, Norway (the mainland and Svalbard), Russia (the arctic and Kamchatka) and Scotland. Although the term 'fjord' is a generic Nordic name for a marine inlet, they are most commonly attributed to having a glacial erosional origin, being formed as land-based glaciers expand through fault-controlled or fluvially eroded troughs. Some fjords are thought to have existed for tens of millions of years since at least the Miocene; for example, Ferrar Valley (Barrett and Hambrey, 1992), Taylor Valley (McKelvey, 1981; Powell, 1981b; Hambrey et al., 1989), Mackay Valley (Powell et al., 1998; 2000), Beardmore Paleofjord (Webb et al., 1996), Reedy Valley (wilson et al., 1998) and Lambert Graben (Hambrey and McKelvey, 2000) in Antarctica, and Ellesmere Island fjords in the Arctic (England, 2000; 0 Cofaigh et al., 2000). Given either these long periods of time or very efficient erosion, fjords range from a few kilometres to several tens of kilometres wide and can be hundreds of kilometres long. Often there are entrance sills or thresholds of bedrock, which also may occur along the fjord axis. Basins separated by these sills may reach depths several hundred metres below sea level. Additionally, fjords are often within tectonically active mountain systems that can reach 5000-6000 m above sea level; therefore, fjord coastlines commonly exhibit some of the greatest relief in the world. Oceanographically, fjords are termed estuaries having some unique characteristics in terms of oceanic processes and characteristics. Understanding these oceanic processes, in addition to the glacial and fluvial processes, is important for interpreting fjord landsystems, and although space does not allow for detailed discussions here, a comprehensive review has been provided by Syvitski et al. (1987), with a more recent short update by Syvtiski and Shaw (1995). As can be discerned from their locations listed above, modern fjords occur under different climatic regimes ranging from temperate through sub-polar to polar (Table 13.1). Different landsystem models have been proposed for these differing conditions (Fig. 13.1), the details of which will be elaborated on through this chapter.

Climatic

Glacial

Internal

Bed condition

Subglacial

Glacier

Sediment contributions*

zone

flow velocity

ice condition

water free

terminus

Glacial

Glacifluvial Marine

Terrestrial

Modern examples

Sub-

En/supra-

Sub- En- Icebergs Sea /supra- ice

Biogenic Fluvial Mass flow

Wind

Temperate

Fast

Temperate

Deforming till, local

Conduit flow

Tidewater cliff

2

2

5 1 2

1 3 3

i

Alaska, British Columbia, Chile

Sub-polar

Fast

Slightly cold

Deforming till

Conduit flow

Tidewater cliff

3

i

3 112

1 3 1

i

Svalbard, Canadian and Russian arctic

Moderate

Cold

Mostly frozen, local till

None to minor conduit flow

Short floating tongue or tidewater cliff

2

2 1

2 1

i

Antarctic Peninsula

Very cold Very cold

Deforming till

Deforming till Mostly frozen, some till

Local conduit thin film None None

Floating tongue

Floating tongue Floating tongue or tidewater cliff

1 1 1 1 1

3 3

Greenland, Ellesmere Island, Baffin Island Antarctica (Mackay) Antarctica (Ferrar and Blue)

^Relative scale estimating importance of sediment source contributions to fjords: 5

=high to 1 =low

Table 13.1 Current data on major local controls on modern fjord landsystems (modified from Syvitski et al. (1987) and Hambrey (1994)).

Table 13.1 Current data on major local controls on modern fjord landsystems (modified from Syvitski et al. (1987) and Hambrey (1994)).

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