When global sea levels are relatively high, as they currently are,
the Bering Strait forms a shallow-water gateway from the Arctic Ocean to
the Bering Sea and Pacific Ocean. During glacial episodes, however, the
Bering Land Bridge emerges in its place to connect Asia and North America.
A planning group is being created within the Nansen Arctic Drilling Program
(NAD) to define scientific objectives and drill sites in this region. Plans
will be based on existing Mineral Management Service (MMS) site surveys and
stratigraphic wells in the Bering Sea. These data, which are from the
Norton, Navarin, Bristol Bay and St. Georges basins, are advantageous for
Quaternary drilling because much is already known from COST (Continental
Offshore Stratigraphic Test) wells. Unfortunately, no continuous coring
data were obtained to provide the details of the paleoenvironmental record.
A meeting is scheduled at the Fall American Geophysical Union (AGU)
conference to seek input from the scientific community for organizing and
preparing an integrated program for scientific drilling on the Bering Land
Scientific objectives unique to the Bering Land Bridge will require
an unusually multidisciplinary approach. Because the Land Bridge is
subaerially exposed during times of low sea level, at least part of the
sedimentary record encountered during drilling is likely to be terrestrial.
It may include peats, lake sediments, loess, terrestrial permafrost and
periglacial features, and glacial deposits. In ideal cases, it will contain
alternating sequences of terrestrial and marine sediments, perhaps
recording dozens of the sea-level changes which occurred throughout the
Pleistocene in response to the climate driven waxing and waning of
continental ice sheets. Volcanism has been important on and around the
margin of the Bering Land Bridge during the Quaternary, thus tephras and
other volcanic deposits will also be present. Furthermore, the Bering Land
Bridge has recently been proposed as an active plate boundary between Asia
and North America, suggesting that neotectonic features are likely be
encountered during scientific drilling.
The Bering Land Bridge meeting will be held at the Moscone Center,
Room 258/260 on Monday, 7 December from 1530-1730. An Ocean Drilling
Program (ODP) town meeting will be held in MC Room 125 at 1730. Those
interested are encouraged to attend the NAD meeting first and then move to
the ODP meeting where coincident drilling interests can be explored.