5) Kathleen Springer & Jeff Pigati
Kathleen Springer and Jeff Pigati, Research Geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver
Kathleen Springer and Jeff Pigati, Research Geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver
One day, two seminars!
Kathleen Springer and Jeff Pigati, Research Geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver
Kathleen Springer and Jeff Pigati, Research Geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver
Monday October 9th; 3 PM
Monday October 9th; 3 PM
Host: Matt Kohn
Host: Matt Kohn
Title: Quaternary Hydroclimate Records of Spring Ecosystems
Title: Quaternary Hydroclimate Records of Spring Ecosystems
Abstract: Kathleen Springer and Jeff Pigati are research geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver, Colorado. They are co-PIs of the Quaternary Hydroclimate Records of Spring Ecosystems project in which they investigate geologic deposits associated with springs and desert wetlands to determine how these fragile ecosystems responded to past episodes of abrupt climate change. Their work has focused on developing stratigraphic and chronologic frameworks from paleowetland deposits throughout the Mojave Desert and southern Great Basin, which then serve as hydroclimate roadmaps for these ecosystems. They have established that spring and desert wetland ecosystems are incredibly sensitive to changes in climate at multi-decadal to centennial timescales and that they expanded and contracted in near lockstep with changes in climate recorded in the Greenland ice cores over the past 40,000 years. These sensitive groundwater dependent ecosystems allow them to evaluate the effects of abrupt warming events on terrestrial landscapes including Dansgaard-Oeschger (D-O) events, which are analogous to projected future warming in terms of their magnitude, timing, and sphere of influence. Notably, their results demonstrate that springs and wetlands in the southwestern U.S. contracted or disappeared altogether during D-O events due to rapid groundwater lowering associated with these megadrought episodes. Their findings have tremendous implications for extant springs in arid environments.
Abstract: Kathleen Springer and Jeff Pigati are research geologists with the U.S. Geological Survey’s Geosciences and Environmental Change Science Center in Denver, Colorado. They are co-PIs of the Quaternary Hydroclimate Records of Spring Ecosystems project in which they investigate geologic deposits associated with springs and desert wetlands to determine how these fragile ecosystems responded to past episodes of abrupt climate change. Their work has focused on developing stratigraphic and chronologic frameworks from paleowetland deposits throughout the Mojave Desert and southern Great Basin, which then serve as hydroclimate roadmaps for these ecosystems. They have established that spring and desert wetland ecosystems are incredibly sensitive to changes in climate at multi-decadal to centennial timescales and that they expanded and contracted in near lockstep with changes in climate recorded in the Greenland ice cores over the past 40,000 years. These sensitive groundwater dependent ecosystems allow them to evaluate the effects of abrupt warming events on terrestrial landscapes including Dansgaard-Oeschger (D-O) events, which are analogous to projected future warming in terms of their magnitude, timing, and sphere of influence. Notably, their results demonstrate that springs and wetlands in the southwestern U.S. contracted or disappeared altogether during D-O events due to rapid groundwater lowering associated with these megadrought episodes. Their findings have tremendous implications for extant springs in arid environments.
Their research is largely conducted on federal lands administered by the National Park Service, including Tule Springs Fossil Beds National Monument, Death Valley National Park, Joshua Tree National Park, Channel Islands National Park, and the Mojave National Preserve. In White Sands National Park, Kathleen and Jeff have combined detailed stratigraphic analyses and cutting-edge dating techniques with their intimate understanding of past climate events to establish the age, geologic context, and paleoenvironmental setting of ancient human footprints recently discovered there – including the link to abrupt climate change that allowed the human and megafaunal footprints and trackways to be created and preserved. Their results have upended traditional models regarding the peopling of the Americas and fundamentally change the very foundation of North American archaeology.
Their research is largely conducted on federal lands administered by the National Park Service, including Tule Springs Fossil Beds National Monument, Death Valley National Park, Joshua Tree National Park, Channel Islands National Park, and the Mojave National Preserve. In White Sands National Park, Kathleen and Jeff have combined detailed stratigraphic analyses and cutting-edge dating techniques with their intimate understanding of past climate events to establish the age, geologic context, and paleoenvironmental setting of ancient human footprints recently discovered there – including the link to abrupt climate change that allowed the human and megafaunal footprints and trackways to be created and preserved. Their results have upended traditional models regarding the peopling of the Americas and fundamentally change the very foundation of North American archaeology.
Bios:
Bios:
Kathleen Springer is a research geologist with the U.S. Geological Survey in Denver, Colorado. She specializes in deciphering complex stratigraphic sequences and reconstructing paleoenvironmental conditions, and studies how springs and other hydrologic systems responded to climate change in the recent geologic past.
Kathleen Springer is a research geologist with the U.S. Geological Survey in Denver, Colorado. She specializes in deciphering complex stratigraphic sequences and reconstructing paleoenvironmental conditions, and studies how springs and other hydrologic systems responded to climate change in the recent geologic past.
Jeff Pigati is a research geologist with the U.S. Geological Survey in Denver, Colorado. His research is focused on understanding the response of hydrologic systems in arid environments to past episodes of abrupt climate change. He is also an expert in radiocarbon dating.
Jeff Pigati is a research geologist with the U.S. Geological Survey in Denver, Colorado. His research is focused on understanding the response of hydrologic systems in arid environments to past episodes of abrupt climate change. He is also an expert in radiocarbon dating.
BONUS TALK!!!
BONUS TALK!!!
Honors College Seminar by Jeff and Kathleen
Honors College Seminar by Jeff and Kathleen
Monday October 9th; 7 PM
Monday October 9th; 7 PM
Where: Boise State University Student Union Building (SUB)
Where: Boise State University Student Union Building (SUB)
Title: Evidence of humans in North America during the Last Glacial Maximum
Title: Evidence of humans in North America during the Last Glacial Maximum
Abstract: Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. Questions remain about when and how people migrated, where they originated, and how their arrival affected the established fauna and landscape. Here, we present evidence from excavated surfaces in White Sands National Park (New Mexico, United States), where multiple in situ human footprints are stratigraphically constrained and bracketed by seed layers that yield calibrated radiocarbon ages between ~23 and 21 thousand years ago. This timing coincided with a Northern Hemispheric abrupt warming event, Dansgaard-Oeschger event 2, which drew down lake levels and allowed humans and megafauna to walk on newly exposed surfaces, creating tracks that became preserved in the geologic record.These findings confirm the presence of humans in North America during the Last Glacial Maximum, adding evidence to the antiquity of human colonization of the Americas and providing a temporal range extension for the coexistence of early inhabitants and Pleistocene megafauna. Independent chronologic controls to confirm the ages is the subject of our ongoing research.
Abstract: Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. Questions remain about when and how people migrated, where they originated, and how their arrival affected the established fauna and landscape. Here, we present evidence from excavated surfaces in White Sands National Park (New Mexico, United States), where multiple in situ human footprints are stratigraphically constrained and bracketed by seed layers that yield calibrated radiocarbon ages between ~23 and 21 thousand years ago. This timing coincided with a Northern Hemispheric abrupt warming event, Dansgaard-Oeschger event 2, which drew down lake levels and allowed humans and megafauna to walk on newly exposed surfaces, creating tracks that became preserved in the geologic record.These findings confirm the presence of humans in North America during the Last Glacial Maximum, adding evidence to the antiquity of human colonization of the Americas and providing a temporal range extension for the coexistence of early inhabitants and Pleistocene megafauna. Independent chronologic controls to confirm the ages is the subject of our ongoing research.
