Sinking of volcanic ash in uncompacted sediment in williams lake, washington.

Ash from the Toba supereruption in Lake Malawi shows no volcanic winter in East Africa at 75 ka.

The most explosive volcanic event of the Quaternary was the eruption of Mt. Toba, Sumatra, 75,000 y ago, which produced voluminous ash deposits found across much of the Indian Ocean, Indian Peninsula, and South China Sea. A major climatic downturn observed within the Greenland ice cores has been attributed to the cooling effects of the ash and aerosols ejected during the eruption of the Younges...

Carbon Cycling and Organic Radiocarbon Reservoir Effect in a Meromictic Crater Lake (lac Pavin, Puy-de-dôme, France)

Lac Pavin is a meromictic maar lake for which the interpretation of sediment radiocarbon dates is complicated by the existence of a largely undefined reservoir effect resulting from degradation of carbon stored in the bottom layer of the water column. A data set of the contemporary 14C distribution of dissolved and particulate organic pools in the water column is presented to address this issue...

Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska

Since the 1980s, nuisance blooms of Didymosphenia geminata (Lyngbye) M. Schmidt have been documented in sites that are warmer and more mesotrophic than historical records indicate. While the invasion of D. geminata in New Zealand is well documented, it is less clear whether nuisance blooms in North America are a new phenomenon. In order to test the hypothesis that D. geminata blooms have increa...

Mass-independent isotopic signatures of volcanic sulfate from three supereruption ash deposits in Lake Tecopa, California

Sources, degradation and recycling of organic matter associated with sinking particles in Lake Michigan

-Sediment trap material collected at five depths from two locations in Lake Michigan has been studied to determine the sources of particulate organic matter and the early diagenetic changes which occur during sinking of particles. Aquatic material dominates in shallower depths whereas land-derived material is more important in near-bottom depths. Organic carbon concentrations decrease with dept...