The Chronology and Stratigraphy of the Little Ice Age. Presented by Sara Peek November 27, 2006. Overview. Background Use of dendrochronology and lichenometry to date coarse warming Varved sediments provide a more continuous climate record Ice core records imply a worldwide event.
Presented by Sara Peek
November 27, 2006
Annual tree rings vary in thickness
Lichen Rhizocarpon geographicumincreases in radius over time
The moraine complex is (i) two inner, relatively barren, fresh-appearing moraines (Moraines 1–2), the second of which (Moraine 2) is considerably larger and overrides the proximal face of Moraine 3; (ii) a middle suite of three sparsely lichen and tree-covered moraines (Moraines 3–5), with the outermost of the three (Moraine 5) being the most prominent; and, (iii) an outer suite of three smaller, forested moraines (Moraines 6–8).
The year associated with each moraine denotes the year that the glacier began to recede; that is, years that climate was warming.
Donard Lake is located in a trough of the global-scale west winds
Warming or cooling changes the position of the trough, so the region is very sensitive to climate shifts
The eastern lobe of the Caribou Glacier may spill across a bedrock saddle to drain into Donard Lake
--Dotted line is summer temperature
I’m not sure I like this plot.
(and trying to explain the variability with rainfall records doesn’t help much.)
Little Ice Age: 1ºC lower than preceding period
Largest Glacier in Peru
55-m-high ice cliff at margin of Quelccaya ice cap. Annual accumulation layers average ¾ m in thickness.
1980 extent of Quelccaya Ice Cap
Ice core stratigraphy accumulation layers average ¾ m in thickness.
Southern and Northern hemisphere temperature records are remarkably similar, implying a global extent for the Little Ice Age.