Evidence for an Early Recent Warm Interval in Northwestern Alaska

Abstract

Research Article| October 01, 1966 Evidence for an Early Recent Warm Interval in Northwestern Alaska DAVID McCULLOCH; DAVID McCULLOCH U.S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar DAVID HOPKINS DAVID HOPKINS U.S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar Author and Article Information DAVID McCULLOCH U.S. Geological Survey, Menlo Park, California DAVID HOPKINS U.S. Geological Survey, Menlo Park, California Publisher: Geological Society of America Received: 26 May 1965 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1966, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1966) 77 (10): 1089–1108. https://doi.org/10.1130/0016-7606(1966)77[1089:EFAERW]2.0.CO;2 Article history Received: 26 May 1965 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation DAVID McCULLOCH, DAVID HOPKINS; Evidence for an Early Recent Warm Interval in Northwestern Alaska. GSA Bulletin 1966;; 77 (10): 1089–1108. doi: https://doi.org/10.1130/0016-7606(1966)77[1089:EFAERW]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A warm interval that began at least 10,000 years ago and lasted until at least 8300 years ago is recorded in the coastal tundra covered area of northwestern Alaska by the presence of fossil wood of tree size or tree species, fossil beaver-gnawed wood found beyond the modern range of beaver, evidence of ice-wedge melting, buried soils, and soils that extend below the top of modern permafrost.Dating of the warm interval is based on eight radiocarbon dates. Although these do not provide tight control for either the beginning or the end, they permit the interpretation that the warm event began at the start of the worldwide, postglacial warming and that it ended at the time of the Anivik Lake glacial readvance in the Brooks Range. If this is correct, the early Recent warm interval and the “postglacial thermal maximum” recognized by Livingstone in the Brooks Range were separated by a period of cooler climate. Deposits 7200 and 3600 years old also record moments when the climate was warmer than at present in coastal northwestern Alaska. Although these may record a continuation of the early Recent warm period, it seems more likely that they represent later and separate brief intervals of warmer climate.A postglacial thermal maximum between 6000 and 3000 years ago is recorded by pollen profiles in the Brooks Range, but is not clearly recorded in the coastal areas of northwestern Alaska. We suggest that as sea level rose to near its present position, the accompanying maritime climate lowered summer temperatures in this coastal area during the time at which areas farther inland were experiencing the high temperatures of the postglacial thermal maximum. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.