this lake-sediment-accumulation record likely reflects summer temperature changes on multi-decadal and longer timescales. It should not be used to infer inter-annual variability, which is controlled by subglacial fluvial processes.
based on studies of glacier mass balance and glaciology in Iceland (e.g. Bjornsson; Flowers), I would agree that Icelandic glacier fluctuations are dominantly controlled by changes in melt season temperature. Glacier fluctuations influence the production and transport of eroded material and the eventual deposition of this sediment in a downstream basin (i.e. a proglacial lake). ... On short timescales (seasonal, annual, inter-annual), changes in sediment accumulation can be driven by many factors and we can all agree that identifying individual controls is messy. But on longer timescales (for example, centennial timescales, ... I would argue strongly that changes in sediment accumulation are driven by changes in glacier size. This is laid out in Larsen et al., 2011 QSR. We subsequently expanded on this initial study to: 1) include the whole Holocene (Larsen et al., 2012 QSR attached, which demonstrates a clear "8.2ka-event" signal and subsequent Neoglacial onset), and 2) by measuring varve thickness in multiple cores along a lake transect and tying the core data to seismic stratigraphy (Larsen et al. 2013 EPSL attached). This latter work demonstrates that the trends in sediment accumulation are consistent and observed throughout the lake basin. Given the available data, I feel comfortable summarizing as follows: Icelandic glacier fluctuations are dominantly controlled by summer temperature. On longer timescales, fluctuations of the Langjokull ice cap can be reconstructed from changes in mean varve thickness at glacial lake 'Hvitarvatn. with instrumental record'
thickness (Arc_021): interpretation2_scope: '' has been replaced by 'climate'
thickness (Arc_021): interpretation3_scope: '' has been replaced by 'isotope'
thickness (Arc_021): interpretation4_scope: '' has been replaced by 'isotope'
thickness (Arc_021): interpretation5_scope: '' has been replaced by 'isotope'
thickness (Arc_021): interpretation1_direction: '' has been replaced by 'negative'
thickness (Arc_021): paleoData_isPrimary: '' has been replaced by 'FALSE'
thickness (Arc_021): paleoData_primaryAgeColumn: '' has been replaced by 'FALSE'
year (PYTU43KVL36): paleoData_isPrimary: '' has been replaced by 'TRUE'
year (PYTU43KVL36): paleoData_primaryAgeColumn: '' has been replaced by 'TRUE'
Updated lipdverse database entry with a changed file.
archiveType: 'lake sediment' has been replaced by 'LakeSediment'
thickness (Arc_021): interpretation1_seasonality: '6 7 8' has been replaced by 'Jun-Aug'
thickness (Arc_021): interpretation1_variable: 'T' has been replaced by 'temperature'
year (PYTU43KVL36): paleoData_units: 'AD' has been replaced by 'yr AD'
Changes made as part of LiPDverse vocabulary standardization process
dataSetName: 'Arc-Hvítárvatn.Larsen.2011' has been replaced by 'Arc-Hvitarvatn.Larsen.2011'
geo_siteName: 'Hvítárvatn' has been replaced by 'Hvitarvatn'
Larsen, Darren J.;Miller, Gifford H.;Geirsdóttir, Áslaug;Thordarson, Thorvaldur
A 3000-year varved record of glacier activity and climate change from the proglacial lake Hvítárvatn, Iceland