GLACIATION IN PENNSYLVANIA

Pothole Repair in Pennsylvania

IN T R O D U C T IO N In the C om m onw ealth of Pennsylvania, the m anual repa ir of potholes involves an annual expend itu re exceeding $25 m illion, which is second only to snow rem oval in the m a in tenance budget. P rior to 1980, it was com m on practice for rep a ir crews to practice a “throw an d go” policy, w ith pa tch m ateria l p laced in the potholes w ithout rem oving debris or lo...

Lyme Disease in Pennsylvania

Neoproterozoic glaciation in the Earth System

The Neoproterozoic contains severe glacial intervals (750–580 Ma) including two extending to low palaeomagnetic latitudes. Paucity of radiometric dates indicates the need for chronostratigraphic tools. Whereas the marine Sr/Sr signatures show a steady rise, C fluctuates, the most reproducible variations being negative signatures in carbonate caps to glacial units, but more diagenetic work is ne...

Glaciation as a migratory switch

Migratory behavior in birds is evolutionarily plastic, but it is unclear how this behavior responded during glacial cycles. One view is that at glacial maxima, species simply shifted their breeding ranges south of glacial ice and remained migratory. To test this hypothesis, we constructed ecological niche models for breeding and wintering ranges of 56 species, finding that 70% of currently long...

Late Quaternary glaciation in the Kyrgyz

The Tien Shan of Kyrgyzstan contains multiple moraines and drift from late Quaternary glaciations. The spatial/temporal distribution of the glaciers inferred from the moraines suggests that the main factor controlling glacier advance here was the availability of moisture. The dominant modern climatic signatures in northern Central Asia include orographic thunderstorms in summer, cold and dry Si...