Reconstructing the groundwater recharge history for the Plymouth-Carver Aquifer Massachusetts, USA

摘要

Groundwater systems can respond to climate forcing and millennial climate shifts more slowly than other components of the hydrologic cycle, making it difficult to reconstruct the influences and responses of groundwater to changing climate. Here, we test the linkage between climate change and groundwater responses by using water level changes situated in areas with permeable, unconfined aquifers systems. For hydroclimate histories, we compare moisture models from terrestrial water level reconstructions with predictions of available water from a transient earth system climate model. We focus our analysis on several small waterbodies with Holocene-era proxy measurements that are connected to the Plymouth-Carver glacial aquifer in southeastern Massachusetts, USA. Using these pond-and marsh-based records, we reconstruct groundwater recharge histories along individual groundwater flow paths using water level and sea level reconstructions with an analytical solution to the groundwater flow equation. We find that the water level reconstructions could contain both hydroclimate and sea level signals, with the early Holocene water levels primarily due to hydroclimate with predominantly a sea level signal after similar to 7.5 ka cal BP. Our results indicate that sea level influenced coastal pond water levels, and sea level may play a more significant role than effective moisture over certain periods in the Holocene for terrestrial water bodies hydraulically connected to the evolving position of the coast. Future climate reconstructions developed from water level histories from low-elevation inland water bodies may benefit from examining the potential influence of sea level in addition to hydroclimate, but additional model validation and consideration of other cryosphere and glacial processes are needed to fully resolve sea level as a driver of terrestrial water level change.