Garry D. McKenzie

Glacial History of the Last Eleven Thousand Years in Adams Inlet, Southeastern Alaska

Thick sections of Wisconsin and younger deposits exposed in recently deglaciated Adams Inlet, Glacier Bay National Monument, southeastern Alaska, reveal the glacial history of the area. Following deposition of the late Wisconsin Granite Canyon till, Forest Creek glaciomarine sediments were laid down. These sediments contain volcanic ash that may have been derived from Mt. Edgecumbe 200 km south of Adams Inlet on Kruzof Island. Wood on top of the Forest Creek sediments is dated at 10,940 ± 155 yrs B.P. Land was nearly 90 m lower than present levels; it rose an average of at least 2 cm per year, causing retreat of the sea. Adams Inlet and tributary valleys were then filled in Hypsithermal time with glacial out-wash and inwash gravel. By 1700 B.P., the entrance to Adams Inlet had been dammed by growing fans forming glacial Lake Adams in the inlet and adjacent valleys. Glacier ice of Neoglacial time then advanced into the lake. Retreat of this ice from the tributary valleys to the central part of the inlet was followed by deposition of a local sandy outwash into the valleys. The time of this retreat and the stabilization of Adams Inlet Glacier possibly coincides with the Little Optimum (A.D. 1150 – 1300). Adams Inlet Glacier then expanded to its maximum Neoglacial extent about A.D. 1700, and it may have remained there as late as 1835. Several glacial lakes formed in tributary valleys during subsequent deglaciation. Deposits of these lakes, glaciofluvial deposits, and till comprise the Glacier Bay Formation in Adams Inlet. Retreat from Neoglacial position is well documented by historical observations.

Airborne laser scanning for high‐resolution mapping of Antarctica

In order to evaluate the potential of airborne laser scanning for topographic mapping in Antarctica and to establish calibration/validation sites for NASAs Ice, Cloud and land Elevation Satellite (ICESat) altimeter mission, NASA, the U.S. National Science Foundation (NSF), and the U.S. Geological Survey (USGS) joined forces to collect high-resolution airborne laser scanning data. In a two-week campaign during the 2001–2002 austral summer, NASAs Airborne Topographic Mapper (ATM) system was used to collect data over several sites in the McMurdo Sound area of Antarctica (Figure 1a). From the recorded signals, NASA computed laser points and The Ohio State University (OSU) completed the elaborate computation/verification of high-resolution Digital Elevation Models (DEMs) in 2003. This article reports about the DEM generation and some exemplary results from scientists using the geomorphologic information from the DEMs during the 2003–2004 field season.

Subject and system in international interaction

Recent interest in cognitive approaches to international interaction in general and international regimes in particular has not been matched by development in theory and methodology. This article details a systematic “subjective” approach that seeks to meet this need. Its claims are developed through its comparison with the accomplishments and shortcomings of more established approaches to the study of international interaction and, in particular, microeconomic formal theory. The subjective alternative can model both individual subjects and the systems in which they are participating. As such, it offers much more in terms of continuities and connections between agents and system structure than do traditional psychological analyses in international relations. The theoretical arguments proceed in the context of a study of cooperation and conflict over Antarctica and its evolving regimes.

Determination of spoil-bank erosion rates in Ohio by using interbank sediment accumulations

Denudation rates of unvegetated spoil banks in Gallia County, Ohio, were determined using sediment volumes and specific weights in four small interbank basins. Calculated rates are higher than those reported from other strip-mined areas because the spoil is unvegetated and consists mainly of friable sandstone. Spoil-bank slopes had erosion rates of 35,000 to 71,000 t · km−2· a−1 (metric tons per square kilometre per year) with an equivalent surface degradation of 2.6 to 5.4 cm· a−1 (centimetres per year). These rates show good correlation with mean slope length, which ranged from 5.8 to 12.8 m. Rates may be higher than calculated owing to loss of material by chemical weathering and subsequent leaching. The study demonstrates the suitability of simple measurements in interbank depressions to obtain average annual erosion rates for drastically disturbed landscapes.

Gondawana Six: Structure, Tectonics, and Geophysics Gondwana Six: Stratigraphy, Sedimentology, and Paleontology

Twenty-one years ago, the first Gondwana Symposium was held in Buenos Aires, Argentina. Since then, five more symposia have explored many aspects of Gondwana geoscience. The sixth symposium, held in Columbus, Ohio, August 19–23, 1985, was the first outside of the southern hemisphere. Many of the papers presented at that symposium appear in this two-volume set, and as was the case with papers presented at the meeting, almost half of the material covers Antarctic problems. This is not unexpected, given the location of the meeting, in the United States at the Institute of Polar Studies (now known as the Byrd Polar Research Center) at the Ohio State University. Many U.S. scientists working on Gondwana problems do so in Antarctica as part of the U.S. Antarctic Research Program