DOI: 10.1016/j.quascirev.2017.12.001
Scopus记录号: 2-s2.0-85038835516
论文题名: Asynchronous glaciations in arid continental climate
作者: Batbaatar J. ; Gillespie A.R. ; Fink D. ; Matmon A. ; Fujioka T.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 182 起始页码: 1
结束页码: 19
语种: 英语
英文关键词: Asynchronous glaciation
; Central Asia
; Holocene
; Pleistocene
; Sublimation
Scopus关键词: Ablation
; Arid regions
; Landforms
; Mapping
; Sublimation
; Asynchronous behavior
; Asynchronous glaciation
; Central Asia
; Equilibrium line altitudes
; Holocenes
; Pleistocene
; Precipitation gradients
; Sub-freezing temperatures
; Glacial geology
; ablation
; arid region
; glaciation
; glacier advance
; glacier dynamics
; heterogeneity
; high temperature
; Holocene
; Last Glacial Maximum
; melting
; mountain region
; numerical model
; Pleistocene
; precipitation (climatology)
; sublimation
; Central Asia
; Mongolia
英文摘要: Mountain glaciers at ∼26–19 ka, during the global Last Glacial Maximum near the end of the last 105 yr glacial cycle, are commonly considered on the basis of dating and field mapping in several well-studied areas to have been the largest of the late Quaternary and to have advanced synchronously from region to region. However, a numerical sensitivity model (Rupper and Roe, 2008) predicts that the fraction of ablation due to melting varies across Central Asia in proportion to the annual precipitation. The equilibrium-line altitude of glaciers across this region likely varies accordingly: in high altitude, cold and arid regions sublimation can ablate most of the ice, whereas glaciers fed by high precipitation cannot ablate completely due to sublimation alone, but extend downhill until higher temperatures there cause them to melt. We have conducted field studies and 10Be dating at five glaciated sites along a precipitation gradient in Mongolia to test the Rupper/Roe model. The sites are located in nearby 1.875 × 1.875° cells of the Rupper/Roe model, each with a different melt fraction, in this little-studied region. The modern environment of the sites ranges from dry subhumid in the north (47.7° N) to arid in the south (45° N). Our findings show that the maximum local advances in the dry subhumid conditions predated the global Last Glacial Maximum and were likely from MIS 3. However, we also found that at ∼8–7 ka a cirque glacier in one mountain range of the arid Gobi desert grew to a magnitude comparable to that of the local maximum extent. This Holocene maximum occurred during a regional pluvial period thousands of years after the retreat of the Pleistocene glaciers globally. This asynchronous behavior is not predicted by the prevailing and generally correct presumption that glacier advances are dominantly driven by temperature, although precipitation also plays a role. Our findings are consistent with and support the Rupper/Roe model, which calls for glaciation in arid conditions only at high altitudes of sub-freezing temperatures, where the melt fraction in ablation is low. We expect a heterogeneous pattern of glacial responses to a changing modern climate in cold arid regions; an individual glacier advance should not be necessarily interpreted as evidence of cooling climate. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112299
Appears in Collections: 气候减缓与适应
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作者单位: Quaternary Research Center, University of Washington, Seattle, WA 98195-1310, United States; Australian Nuclear Science and Technology Organisation, PMB1, Menai, 2234, Australia; The Institute of Earth Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, 91904, Israel
Recommended Citation:
Batbaatar J.,Gillespie A.R.,Fink D.,et al. Asynchronous glaciations in arid continental climate[J]. Quaternary Science Reviews,2018-01-01,182