Research Themes: Paleorotation
Linda A. Hinnov
In development, Fall 2014:
Twentieth century lunar laser ranging and historical eclipse observations provide direct evidence of lunar recession and change in length-of-day for the past 2500 years. For earlier times, a handful of uncoordinated paleontological (corals, bivalves) and sedimentary ("tidalite") data offer quantitative snapshots of days per year back to 2.5 Ga. A third archive not yet assessed is cyclostratigraphy: faster rotation rates in deep time should translate into faster precession. A paleorotation database is needed to consolidate (and reanalyze) legacy data. New entries to this database will entail assessment of obliquity and precession frequencies from cyclostratigraphy. Finally, the analysis of a potential tidalite from the >3.7 Ga Isua Formation may provide the oldest quantitative data pertaining to Earth-Moon dynamics.
Current paleorotation projects:
A Paleorotation Database
Paleozoic Milankovitch Cycles
Precambrian Milankovitch Cycles