1. Department of Earth Sciences; University of Southern California; Los Angeles California USA
2. Department of Geology and Earth System Science Interdisciplinary Center; University of Maryland; College Park Maryland USA
3. Geophysical Institute, University of Alaska Fairbanks; Fairbanks Alaska USA
4. Department of Earth and Space Sciences; Quaternary Research Center, University of Washington; Seattle Washington USA
5. National Center for Atmospheric Research; Boulder Colorado USA