Neopluvial

Neopluvial is a term referring to a phase of wetter and colder climate in the western United States in the late Holocene,[1] causing the levels of lakes in the Great Basin to increase[2] and previously dry lakes and springs to refill.[3] It is in part correlative to the Neoglacial,[4] and might have been caused by a change in winter time conditions over the North Pacific.[5] It resembles the pluvial period that occurred in western North America during the late last glacial maximum,[6] but was much weaker than the LGM wet period.[7]

It has been observed in Great Salt Lake,[7] Fallen Leaf Lake,[8] Lake Cochise,[9] the Mojave Desert,[10] Mono Lake, Owens Lake, Pyramid Lake,[8] San Luis Lake,[9] Silver Lake,[10] Summer Lake,[11] Tulare Lake[12] and Walker Lake.[8]

During the Neopluvial, the Great Salt Lake became fresher,[7] Pyramid Lake reached a water level of 1,186 metres (3,891 ft) above sea level;[8] there is evidence for at least two highstands.[13] Walker Lake, Owens Lake and Mono Lake experienced their highest Holocene water levels,[8] with the volumes of the latter two lakes more than doubling.[14] Likewise water levels in Lake Tahoe rose to the point of overflowing into the Truckee River.[15] Silver Lake in the Mojave Desert formed a perennial lake and vegetation was more widespread in the Little Granite Mountains.[10] Summer Lake rose above its present day level to an elevation of c. 1,278 metres (4,193 ft),[16] although it was not as high as during the mid-Holocene.[11] Water levels rose in Tulare Lake as well.[12]

In the White Mountains, meadows formed during the Neopluvial.[17] Glaciers grew in the Sierra Nevada,[13] sagebrush steppe, green mormon tea and other vegetation expanded in the Great Salt Lake region,[18] marshes expanded in the central and northern Great Basin,[4] mammal communities in the Lake Bonneville basin changed,[19] and tree lines dropped, with the lower limit of wooden vegetation penetrating into deserts.[20] Counterintuitively, higher tree line elevations in the Lake Bonneville area occurred during the Neopluvial.[21] In the Owens Valley region, during the Neopluvial the population became more sedentary and trans-Sierra Nevada trade became established ("Newberry"/"Middle Archaic Period").[22] Population around Lake Alvord increased during this time and lasted even after the Neopluvial had ended there.[3]

The beginning of the Neopluvial occurred about 6,000 years before present, but did not occur everywhere at the same time. Rising water levels in Lake Tahoe drowned trees between 4,800 and 5,700 years before present.[15] In the Great Salt Lake, the Neopluvial commenced 5,000 years before present and water levels reached their maximum between 3,000 and 2,000 years before present.[7] In Pyramid Lake, the Neopluvial commenced starting from 5,000 years before present and reached a maximum between 4,100 - 3,800 years before present in Pyramid Lake,[8] between 4,000 and 2,000 years before present in the Carson Sink,[13] between 3,000 - 4,000 years before present in Lake Cochise,[9] between 5,100 and 2,650 years before present in the central-northern Great Basin,[4] between 4,000 and 2,500 years before present in the Mojave Desert,[10] between 4,000 and 1,900 years ago in the Summer Lake area,[16] and 3,700 years before present in Fallen Leaf Lake. The end of the Neopluvial in Fallen Leaf Lake occurred 3,650 years before present;[8] after that point precipitation became more irregular until the onset of the Little Ice Age about 3,000 years later.[23] In Tulare Lake, the Neopluvial lasted between 4,500 and 2,800 years before present; after that a severe drought occurred.[12] The Neopluvial in the Lake Lahontan basin ended about 2,000 years ago.[3]

The term "neopluvial" has also been used for a mid-to-late Holocene phase of increased moisture noted in the form of increased wetness in eastern Texas, potentially linked to a stronger monsoon.[24]

References

  1. ↑ Hockett 2015, p. 293.
  2. ↑ Hockett 2015, p. 299.
  3. 1 2 3 PETTIGREW, RICHARD M. (1984). "Prehistoric Human Land-use Patterns in the Alvord Basin, Southeastern Oregon". Journal of California and Great Basin Anthropology. 6 (1): 82–83 – via https://escholarship.org/uc/item/83g062fb.
  4. 1 2 3 Hockett 2015, p. 292.
  5. ↑ Yuan, Koran & Valdez 2013, p. 157.
  6. ↑ Yuan, Koran & Valdez 2013, p. 158.
  7. 1 2 3 4 Madsen 2000, p. 157.
  8. 1 2 3 4 5 6 7 Noble, Paula; Zimmerman, Susan; Ball, Ian; Adams, Kenneth; Maloney, Jillian; Smith, Shane (2016-04-01). "Late Holocene subalpine lake sediments record a multi-proxy shift to increased aridity at 3.65 kyr BP, following a millennial-scale neopluvial interval in the Lake Tahoe watershed and western Great Basin, USA". 18: 7533.
  9. 1 2 3 Yuan, Koran & Valdez 2013, p. 155.
  10. 1 2 3 4 Jones, Terry L.; Klar, Kathryn; Archaeology, Society for California (2007). California Prehistory: Colonization, Culture, and Complexity. Rowman Altamira. p. 33. ISBN 9780759108721.
  11. 1 2 "AN EARTHQUAKE CLUSTER FOLLOWED THE DRYING OF PLEISTOCENE LAKE CHEWAUCAN, CENTRAL OREGON BASIN AND RANGE". gsa.confex.com. Retrieved 2017-07-06.
  12. 1 2 3 Negrini, Robert M.; Wigand, Peter E.; Draucker, Sara; Gobalet, Kenneth; Gardner, Jill K.; Sutton, Mark Q.; Yohe, Robert M. (2006-07-01). "The Rambla highstand shoreline and the Holocene lake-level history of Tulare Lake, California, USA". Quaternary Science Reviews. 25 (13): 1614. doi:10.1016/j.quascirev.2005.11.014.
  13. 1 2 3 Noble et al. 2016, p. 207.
  14. ↑ "HOW WET CAN IT GET? DEFINING FUTURE CLIMATE EXTREMES BASED ON LATE HOLOCENE LAKE-LEVEL RECORDS". gsa.confex.com. Retrieved 2017-07-06.
  15. 1 2 Noble et al. 2016, p. 206.
  16. 1 2 Badger, Thomas C.; Watters, Robert J. (2004-05-01). "Gigantic seismogenic landslides of Summer Lake basin, south-central Oregon". GSA Bulletin. 116 (5-6): 619. ISSN 0016-7606. doi:10.1130/B25333.1.
  17. ↑ Ababneh, Linah; Woolfenden, Wallace (2010-03-15). "Monitoring for potential effects of climate change on the vegetation of two alpine meadows in the White Mountains of California, USA". Quaternary International. 23rd Pacific Climate Workshop (PACLIM). 215 (1): 4. doi:10.1016/j.quaint.2009.05.013.
  18. ↑ Madsen 2000, p. 161.
  19. ↑ Oviatt & Shroder 2016, p. 363-364.
  20. ↑ Westfall, Robert D; Millar, Constance I (2004-08-11). "Genetic consequences of forest population dynamics influenced by historic climatic variability in the western USA". Forest Ecology and Management. Dynamics and Conservation of Genetic Diversity in Forest Ecology. 197 (1): 160. doi:10.1016/j.foreco.2004.05.011.
  21. ↑ Oviatt & Shroder 2016, p. 278.
  22. ↑ Ababneh, Linah (2008-09-01). "Bristlecone pine paleoclimatic model for archeological patterns in the White Mountain of California". Quaternary International. The 22nd Pacific Climate Workshop. 188 (1): 63. doi:10.1016/j.quaint.2007.08.041.
  23. ↑ Noble et al. 2016, p. 208.
  24. ↑ Wilkins, David E.; Currey, Donald R. (1999-04-01). "Radiocarbon chronology andδ13C analysis of mid-to late-Holocene aeolian environments, Guadalupe Mountains National Park, Texas, USA". The Holocene. 9 (3): 368. ISSN 0959-6836. doi:10.1191/095968399677728249.

Sources

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.