DOI: 10.1016/j.quascirev.2015.07.025
Scopus记录号: 2-s2.0-84939147666
论文题名: Spatial variability of tephra and carbon accumulation in a Holocene peatland
作者: Watson E.J. ; Swindles G.T. ; Lawson I.T. ; Savov I.P.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 124 起始页码: 248
结束页码: 264
语种: 英语
英文关键词: Geochronology
; Ireland
; Peatlands
; Spheroidal carbonaceous particles
; Tephrostratigraphy
; Volcanic ash
Scopus关键词: Deposition
; Geochronology
; Stratigraphy
; Volcanoes
; Ireland
; Peat land
; Spheroidal carbonaceous particles
; Tephrostratigraphy
; Volcanic ash
; Wetlands
; carbon sequestration
; chronostratigraphy
; disturbance
; Holocene
; human activity
; paleoenvironment
; peatland
; proxy climate record
; reconstruction
; spatial distribution
; spatial variation
; spatiotemporal analysis
; tephra
; tephrochronology
; volcanic ash
; Iceland
; Ireland
英文摘要: Microscopic tephra layers ('cryptotephras') represent important age-equivalent stratigraphic markers utilised in many palaeoenvironmental reconstructions. When used in conjunction with proximal records of volcanic activity they can also provide information about volcanic ash cloud fallout and frequency. However, the spatial distributions of tephra layers can be discontinuous even within the same region. Understanding the deposition and post-depositional redistribution of tephra is vital if we are to use cryptotephras as records of ash cloud occurrence and chronostratigraphic markers. The discrete nature of tephra layers also allows for detailed study into processes of deposition and reworking which affect many palaeoenvironmental proxy records.We undertook a multi-core study in order to examine the historical tephrostratigraphy of a raised peatland in Northern Ireland. Three tephra layers originating from Iceland (Hekla 1947, Hekla 1845 and Hekla 1510) are present in 14 of the 15 cores analysed. This suggests that in areas not influenced by snowfall or anthropogenic disturbance at the time of tephra delivery, the presence or absence of a tephra layer is generally consistent across a peatland of this type. However, tephra shard counts (per unit area) vary by an order of magnitude between cores. These intra-site differences may confound the interpretation of shard counts from single cores as records of regional ash cloud mass/density. Bootstrap resampling analysis suggests that total shard counts from multiple cores are required in order to make a reliable estimate of median shard counts for a site. The presence of three historical tephras in 14 cores enables a spatio-temporal analysis of the long-term apparent rate of carbon accumulation (LARCA) in the peatland. Substantial spatial and temporal variations in LARCA are identified over the last ~450 years. This high variability needs to be taken into account when designing studies of peatland carbon accumulation. © 2015 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59846
Appears in Collections: 过去全球变化的重建
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作者单位: School of Geography, University of Leeds, Leeds, United Kingdom; Department of Geography and Sustainable Development, University of St Andrews, St Andrews, United Kingdom; School of Earth and Environment, University of Leeds, Leeds, United Kingdom
Recommended Citation:
Watson E.J.,Swindles G.T.,Lawson I.T.,et al. Spatial variability of tephra and carbon accumulation in a Holocene peatland[J]. Quaternary Science Reviews,2015-01-01,124