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J. McGill

Publications and source records attributed to J. McGill.

2 recordsLinked to original sources

Paleolimnological investigations of anthropogenic environmental change in Lake Tanganyika: I. An introduction to the project

We investigated paleolimnological records from a series of river deltas around the northeastern rim of Lake Tanganyika, East Africa (Tanzania and Burundi) in order to understand the history of anthropogenic activity in the lake's catchment over the last several centuries, and to determine the impact of these activities on the biodiversity of littoral and sublittoral lake communities. Sediment pollution caused by increased rates of soil erosion in deforested watersheds has caused significant changes in aquatic communities along much of the lake's shoreline. We analyzed the effects of sediment discharge on biodiversity around six deltas or delta complexes on the east coast of Lake Tanganyika: the Lubulungu River delta, Kabesi River delta, Nyasanga/Kahama River deltas, and Mwamgongo River delta in Tanzania; and the Nyamuseni River delta and Karonge/Kirasa River deltas in Burundi. Collectively, these deltas and their associated rivers were chosen to represent a spectrum of drainage-basin sizes and disturbance levels. By comparing deltas that are similar in watershed attributes (other than disturbance levels), our goal was to explore a series of historical "experiments" at the watershed scale, with which we could more clearly evaluate hypotheses of land use or other effects on nearshore ecosystems. Here we discuss these deltas, their geologic and physiographic characteristics, and the field procedures used for coring and sampling the deltas, and various indicators of anthropogenic impact. ?? Springer 2005.

Journal of Paleolimnology↗

Seismic survey of Lake Baikal, Siberia cruise report: RV Balkhash 25 August to 25 September 1992

Introduction A comprehensive multichannel seismic-reflection (MCS) and ocean bottom seismometer (OBS) seismic-refraction survey of Lake Baikal, Siberia was undertaken during August-September 1992 as a collaborative research project by U.S. and Russian scientists. This project was supported by funding from the U.S. Geological Survey, the U.S. National Science Foundation and the Russian Academy of Sciences. Over 2200 km of multichannel seismic-reflection data on 42 profiles and over 500 km of seismic-refraction data on 4 OBS profiles were acquired during this study. On board seismic processing facilities were utilized for quality control and demultiplexing of seismic data during the cruise. Lost survey time due to weather was about 7 days, but most planned seismic profiling was completed, including the reshooting of profiles where necessary. This seismic study was carried out on two vessels, the RV BALKHASH for MCS work and the TITOV for OBS deployments. This report summarizes the general seismic program and the operations on the BALKHASH. Operations on the TITOV are summarized in a companion report by tenBrink and others. A detailed description of the logistical and technical aspects of the seismic program, including all seismic systems, is given in the companion report by Nichols and others.

Siberia↗