02176nas a2200265   4500000000100000000000100001008004100002653001500043653001200058653001800070653002500088653002300113100001500136700001700151700001600168700001400184700001700198700001600215245008900231856007100320300001200391490000700403520148600410020001401896       2010                            d10aChironomid10aIceland10aLake sediment10aLittle Ice Age (LIA)10aSummer temperature1 aP. Langdon1 aC. Caseldine1 aI. Croudace1 aS. Jarvis1 aWasteg\r ard1 aT. Crowford00aA chironomid-based reconstruction of summer temperatures in NW Iceland since AD 1650  uhttp://www.sciencedirect.com/science/article/pii/S0033589410001420  a451-4600 v753 aFew studies currently exist that aim to validate a proxy chironomid-temperature reconstruction with instrumental temperature measurements. We used a reconstruction from a chironomid percentage abundance data set to produce quantitative summer temperature estimates since AD 1650 for NW Iceland through a transfer function approach, and validated the record against instrumental temperature measurements from Stykkish\ olmur in western Iceland. The core was dated through Pb-210, Cs-137 and tephra analyses (Hekla 1693) which produced a well-constrained dating model across the whole study period. Little catchment disturbance, as shown through geochemical (Itrax) and loss-on-ignition data, throughout the period further reinforce the premise that the chironomids were responding to temperature and not other catchment or within-lake variables. Particularly cold phases were identified between AD 1683\textendash1710, AD 1765\textendash1780 and AD 1890\textendash1917, with relative drops in summer temperatures in the order of 1.5\textendash2\textdegreeC. The timing of these cold phases agree well with other evidence of cooler temperatures, notably increased extent of Little Ice Age (LIA) glaciers. Our evidence suggests that the magnitude of summer temperature cooling (1.5\textendash2\textdegreeC) was enough to force LIA Icelandic glaciers into their maximum Holocene extent, which is in accordance with previous modelling experiments for an Icelandic ice cap (Langjökull).  a0033-5894