Key words: lichens, reindeer, Pribilof Islands, grazing pressure, climate change, island ecosystem, lichenometry
, fur seals
Assuming familiarity with basic geologic principles, he discusses how techniques such as lichenometry
(using the growth rates of lichens) can help determine which faults are still active, time of most recent event, and their frequency and magnitude.
Techniques of this science, called lichenometry, were used to determine the age of the giant stone heads on Easter Island.
Using lichenometry (li-chen-omet-ry), scientists use lichens to determine how old rocks and glaciers are.
A variety of methods has been used to identify and date former glacier margins in the Rockies, including geomorphic analysis, stratigraphic and sedimentological observations, radiocarbon dating of fossil plants in glacial sediments, dendrochronology, and lichenometry
. Changes in tree growth at high elevations and changes in sediment delivery to proglacial lakes have also been used to infer climate and glacier fluctuations during the Holocene (Leonard, 1997; Luckman, 2000).
This method, called lichenometry
, has been successfully used to date the age of moraines and other glacial features in the Northeast and rock slides in the Sierra Nevada.
This technique, "lichenometry
", has revealed that the moraines in the southern Urals formed very recently, little more than 700 years ago, between 1230 and 1270 A.D.
The few available chronological data are mainly derived from radiocarbon dating (Denton and Stuiver, 1966; Rampton, 1970), limited dendrochronology (Sharp, 1951), lichenometry
(Denton and Karlen, 1977), and indirect dating of related features such as glacial lake shorelines (Clague and Rampton, 1982).
Dating rock surfaces by lichen growth and its application to glaciation and physiography (lichenometry