Investigation of climatic change mechanisms and process linkages within the Pacific Coastal Region of California-Oregon, through analysis of cave deposits and modern processes

The purpose of this proposed research is to pursue an investigation of the nature of climatic change in the Pacific Coastal Region, through the study of cave deposits and analysis of modern snowmelt and karst solutional processes. The geographic study area is the Klamath Mountains of northern California and southern Oregon, where alpine karst systems have developed under a coupling of cyclic glacial and karst processes, and where cave deposits provide a record of past events. Samples from in-cave depositional sequences will be interpreted using isotope and chemical fingerprinting dating methods (applied to carbonate speleothems and tephra materials), remanent magnetism of tephra, and pollen analysis (for vegetation history). Geomorphic process research, currently focusing on karst solutional processes, will be further enhanced by the initiation of a snowmelt process investigation in order to better derive a picture of modern conditions. Modern glaciokarstic analogs in the Canadian Rockies will be used to investigate how such systems operate when glaciers are active. This research will be used to test current models of alpine karst development and climatic change.

Procedure

The proposed study will involve (1) collection and analysis of deposits from cave systems in the Klamath Range, in cooperation with researchers investigating deposits from other locations using similar methods; (2) investigation of modern glaciokarstic analogs in the Canadian Rockies, in cooperation with researchers working in those areas; (3) continuation of ongoing karst process studies in the area; and (4) initiation of snowmelt mechanism studies, to improve models relating climatic change and glaciation, in cooperation with researchers investigating other world sites.

Intellectual or Creative Significance

Understanding past climatic changes and their impacts is critical to an understanding of the nature of changing environments today, especially important in light of the recently accelerated impacts of humans on our environment and the impact of environmental changes on human activities and the stability of ecosystems. Alpine karst may provide a key to an understanding of past and future climatic fluctuations of northern California and the Pacific Coastal Region. The coevolution of karst and glacial geomorphic systems in the Klamath Ranges of northern California and southern Oregon provides a unique laboratory for studying both karst and glacial geomorphic processes, and for observing the impacts of significant climatic fluctuations -- expressed in glacial advances and retreats. The presence of caves in karst systems provides a site for accumulation and preservation of sediments and carbonate speleothems, which may store information about past climates and vegetation communities that flourished under conditions different from today's.This proposed research makes several contributions: (1) increased understanding of the history of environmental changes in the region; (2) development of new techniques (in data logging) and source materials (cave samples); and (3) testing of techniques and comparison of results with scientific investigations in other sites worldwide (Antarctic snowmelt research; speleothem dating and pollen analysis in North America and Africa). Our knowledge of present and past geomorphic systems in particular is very limited, largely as a result of the difficult nature of the field studies required; and considerably more field research is needed before we can understand the impact of human activity upon these systems. The Marble Mountains Wilderness Area provides a laboratory for studying an environment relatively unaltered by human activity. Still, transhumant cattle grazing is allowed in parts of the Wilderness during part of the year, and recreational use is significant. The proposed research may help evaluate seasonal impacts of these uses on water quality.