Arctic charr from Ennerdale water - relicts of the ice age

The work discussed in this report deals with aspects of the ecology of Arctic charr (Salvelinus alpinus, L.). The main aims of the study were: (1) To assess the relative abundance of migrants entering the River Liza and Smithy Beck in the English Lake District). (2) To assess the degree of stream specificity. (3) To determine the period of residency in the streams. (4) To obtain a better understanding of migratory behaviour. (5) To determine the growth rate of mature fish. (6) To determine the morphometric and meristic attributes. In conjunction with this work a study was carried out to investigate the feasibility of using a video recording system to monitor the migration of charr in Smithy Beck.

An overview of 1000 years of tropical climatic variability from ice cores from the Andes of southern Peru [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Each summer between 1976 and 1984 research was conducted on the Quelccaya Ice Cap with one central objective, to recover an ice core to bedrock from which an approximate 1000 year climatic history for tropical South America could be reconstructed. In 1983 that central objective was accomplished by recovering one core 155 meters in length containing 1350 years and a second core of 163.6 meters containing more than 1500 years of climatic history. ... The most significant climatic event in tropical South America over the last 1500 years was the "Little Ice Age" which is recorded between 1490 to 1880 A.D. in these ice core records. Records from the summit of the Quelccaya Ice Cap show that during the "Little Ice Age" period there was (1) a general increase in particulates (both insoluble and soluble, starting around 1490 A.D. and ending abruptly in 1880 A.D.; (2) an initial increase in net accumulation (1500-1720 A.D.) followed by a period of decreased net accumulation (1720-1860 A.D.); (3) more negative delta-O-18 values beginning in the 1520's and ending around 1880 A.D. The "Little Ice Age" event is evident as a perturbation in all five ice core parameters.

Climatic indicators in an ice core from the Yukon [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Stable isotope data obtained from snow and ice cores retrieved from an altitude of 5340m on Mt. Logan (60°30'N; 140°36'W) indicate that "isotopic seasons" are not generally in phase with calendar seasons. The former are phase lagged with respect to the latter by up to several months and appear to be correlated with SST'S and ocean heat transfer curves and/or the position of the Aleutian low rather than with air temperature or the temperature difference between the ocean surface and the core site.

Paleoenvironmental records from the Quelccaya ice cap, Peru and preliminary results from the Dunde ice cap, China [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The 1000 year records of particulate deposition (soluble and insoluble), oxygen isotopic ratios, and net accumulation from the Quelccaya ice cap are presented. The net accumulation record from Quelccaya is shown to serve as a reasonable proxy for the water levels in Lake Titicaca. ... The ice core record from the Dunde ice cap offers the potential to reconstruct a very detailed history of environmental conditions on the Tibetan Plateau for the last 3000 years.

Initial global perspective of climate for the last thousand years: the ice core record

Climatic and environmental records from low, middle, and high latitude ice cores greatly increase our knowledge of the course of past events. This historical perspective is essential to predict climatic oscillations, dominated as they may be by increasing greenhouse gas concentrations. Forcing factors, internal and external, that have operated in the past will continue to influence the course of events.

The Little Ice Age: glacier variations and climate since AD 1250 [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): During the past hundred years, mountain glaciers throughout the world have retreated significantly from moraines built during the previous several centuries. In the 1930s, Francois Matthes of the U.S. Geological Survey concluded that the moraines represent the greatest advances of glaciers since the end of the last glacial age, some 10,000 years earlier, and informally referred to this late Holocene interval of expanded ice cover as the Little Ice Age.