| “We travelled in the winter after the return of daylight and did not go into fixed camp until
spring, when the ice broke up. There was good hunting on the way, seals, beluga,
walrus, bear.” (From Old Merkrus-rk’s account of his childhood’s trek from Baffin
Island to Northwest Greenland, told to Knud Rasmussen on Saunders Island in
1904)
Five thousand years ago people moving eastwards from Beringia spread over the barrens
of the Canadian high Arctic. This was the first of three waves of prehistoric Arctic “cultures”,
which eventually reached Greenland. The passage into Greenland has to go through the
northernmost and most hostile part of the country with a 5 month Polar night, and to
understand this extraordinary example of human behaviour and endurance, it has been
customary to invoke a more favourable (warmer) climate. This presentation suggests that
land-fast sea ice, i.e. stationary sea ice anchored to the coast, is among the most important
environmental factors behind the spread of prehistoric polar cultures. The ice provides the
road for travelling and social communion - and access to the most important source of food,
the ocean.
In the LongTerm Project (2006 and 2007) we attempted to establish a Holocene record for
sea ice variations along oceanic coasts in northernmost Greenland. Presently the coasts north
of 80Ë N are beleaguered by year-round sea ice - for ten months this is land-fast ice, and only
for a period in the stormy autumn months are the coasts exposed to pack-ice. This
presentation
Land-fast ice – as opposed to pack-ice – is a product of local temperatures, but its
duration over the year, and especially into the daylight season, is also conditioned by other
factors, notably wind strength. In the geological record we recognize long lasting land-fast
ice by two absences: absence of traces of wave action (no beach formation), which, however,
can also be a result of pack-ice along the coast; - and absence of driftwood on the shore
(land-fast ice blocked its landing). Our record shows that a period with less sea ice than now
ended shortly after 6 kaBP. When the Independence I people (4450-3850 kaBP)
came into the area, the sea ice conditions may have been similar to the present with
land-fast ice for a good part of the year. The annual insolation was 2-3% higher
than now, but the vegetation, especially in coastal areas, had deteriorated to Polar
desert, as at present. This development continued, and when the second wave of
immigrants came, The Independence II people (2900-2300 kaBP), both sea-ice
conditions and insolation were similar to the present. Finally, when the last group of
immigrants, the Thule people (AD1400-1500), reached the area had year-round land-fast
ice.
These results show that there is no clear correlation between climate change
and human migration into Greenland, but it may have been the increase in sea ice
after 6 kaBP that paved the ground for the peopling of high Arctic Canada and
Greenland. The three North Greenland immigration-waves took place in a “deteriorating“
(cooling) climate, and evidence from lake sediments and ice coring show that the
immigrants met an environment that was similar to today’s – or even more harsh. |