1. Monthly archive

April 2021

Progress report on reanalysis of the Hawley-Bell collection: Tree-ring chronology building and 14C dating at the religious and political centers of pre-contact eastern North America

During the twelfth century A.D. Indigenous societies across the Mississippi River Basin transformed: populations aggregated into towns around dramatic monumental constructions that represented the seat of polities, communities adopted foreign styles, and more centralized leadership roles emerged. While the general outline of Mississippian history is known, exactly how people came to abandon old cultural practices in favor of the Mississippian pattern is not understood, nor are the historical details of individual mound centers.

The Missouri River: A Story of Two Basins

The Missouri River is unusual because of its two main source regions, one in the high headwaters and one close to the mouth of the river.  In this talk, I report the results of research which explored the hydroclimatology of the basin to better understand the climatic controls on the two parts of the basin, the contribution of the snowmelt-driven streamflow to total Missouri River flow, and the nature of droughts in the instrumental record.  I will also discuss the first comprehensive set of streamflow reconstructions for the upper Missouri River, and the Turn-of-the-21st Century

High-resolution field reconstructions of Mediterranean hydroclimate during the last millennium

The Mediterranean region is projected to experience severe drying trends and more extreme hydroclimate events as a consequence of anthropogenic climate change over the next century.   In some places, this signal may have already emerged from natural variability.  Here we provide content for recent and future changes using new high-resolution spatial reconstructions of multiple hydroclimate fields from a tree-ring network that spans the last millennium.