Rise and fall of late Pleistocene pluvial lakes in response to reduced evaporation and precipitation: Evidence from Lake Surprise, California

摘要: Widespread late Pleistocene lake systems of the Basin and Range Province indicate substantially greater moisture availability during glacial periods relative to modern times, but climatic factors that drive changes in levels are poorly constrained. To better constrain these forcing factors, we present a new lacustrine paleoclimate record precipitation estimates for Lake Surprise, closed basin northeastern California. We combine detailed analysis hydrography constitutive relationships describing water balance determine influence precipitation, evaporation, temperature, seasonal insolation on past levels. At its maximum extent, last deglaciation, Surprise covered 1366 km 2 (36%) terminally draining Valley watershed. Using paired radiocarbon 230 Th-U analyses, dated shoreline tufa deposits from wave-cut terraces Valley, California, most recent cycle. This hydrograph places highest level 176 m above present-day playa at 15.19 ± 0.18 calibrated ka ( 14 C age). significantly postdates Last Glacial Maximum (LGM), when stood only moderate levels, 65–99 playa, similar nearby Lahontan. evaluate associated with lake-level changes, use an oxygen isotope mass model combined predictions Paleoclimate Model Intercomparison Project 3 (PMIP3) climate ensemble. Our predicts minimal increases 2%–18% LGM modern, compared ∼75% increase highstand. PMIP3 simulations corroborate findings, simulating average 6.5% accompanied by 28% decrease total evaporation driven 7 °C mean annual temperature. also suggest decoupling runoff peak shifting spring–early summer winter–early spring. coupled analyses were result reduced temperatures, not increased precipitation. Reduced primed systems, particularly smaller, isolated basins such as respond rapidly late-Heinrich Stadial 1 (HS1). Post-LGM highstands potentially rainfall HS1 brought latitudinally extensive strengthened midlatitude westerly storm tracks, effects which recorded region9s records. These results temperatures have been underinvestigated long-term drivers western United States.