COSMOGENIC 10BE SURFACE EXPOSURE DATING OF LATE HOLOCENE MORAINES OF THE HOOKER GLACIER, SOUTHERN ALPS, NZ
We use a suite of 10Be surface exposure ages from well-preserved moraines of the Hooker Glacier to construct a chronology of moraine deposition tracing the retreat of the Hooker Glacier since about 1500 y.b.p. Since that time, the Hooker Glacier was at or near its maximum extent during the period of the European MCO. Moraines constructed during the European LIA are inboard of those constructed during the MCO and record progressively smaller glacier extents throughout the LIA. In contrast, European records of glacier extent (e.g. Holzhauser, et al., 2005) indicate that glaciers in the Alps occupied retracted positions during the MCO and readvanced beyond those positions during the LIA. 10Be surface exposure dating of moraines of the Hooker Glacier indicates that Late Holocene climate in New Zealand’s Southern Alps did not match the well-known European climate variations during the Medieval Climate Optimum and Little Ice Age. During the past century, the Hooker Glacier has undergone extensive recession from the positions it occupied during the European LIA, part of a global pattern of glacier recession in post-industrial time.