Dendrochronological Assessment of the Easton Glacier\u27s Terminus Position Over the Last 150 Years

The Easton glacier on Mt. Baker, Washington has been the focus of several studies looking at ecological succession, glacier recession, and glacier mass balance. Several of these studies have noted a gap in the literature regarding the Easton glaciers terminus position in the early twentieth century. This study has refined the glacier\u27s terminus position by using dendrochronological methods and identified the latest Little Ice Age end moraines. A chronology of the Easton glaciers terminus position overtime was created showing its recession and advancement since 1879. The rates of recession and advancement were calculated during this time highlighting the unpredictable behavior of glacial systems. By 1956, the Easton glacier had retreated a total of 2,708 meters since 1879. Between 1879 and 1910 the glacier retreated slowly, followed by a 25 year period of rapid retreat where the glacier retreated 1.87 kilometers. The retreat slowed until 1956, when the glacier began a period of advancement. Since 1990 the glacier has been in retreat, which has accelerated over the last few years. This study has also determined ecesis, the interval between deglaciation to vegetation establishment. Ecesis is about 9 years at the bottom of the foreland and 27-28 years at the top of the foreland. This trend of longer ecesis intervals at higher elevations reflects the colder conditions, poorer soil conditions and larger distance from seed sources compared to lower elevations. The findings from this study are only estimates but can still be used to inform on the Easton glaciers response to climate change and other environmental factors