#----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:15309 # Online_Resource: ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/iceland/hvitarvatn2012-varve-psv.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2013-06-29 #-------------------- # Title # Study_Name: Non-linear Holocene climate evolution in the North Atlantic: a high-resolution, multi-proxy record of glacier activity and environmental change from Hvítárvatn, central Iceland #-------------------- # Investigators # Investigators: Larsen,D.J.;Miller,G.H.;Geirsdóttir,Á.;Ólafsdóttir,S. #-------------------- # Description_and_Notes Description: #-------------------- # Publication # Authors: Larsen, D.J., Miller, G.H., Geirsdottir, A., Olafsdottir, S. # Published_Date_or_Year: 2012 # Published_Title: Non-linear Holocene climate evolution in the North Atlantic: a high resolution, multi-proxy record of glacier activity and environmental change from Hvitarvatn, central Iceland. # Journal_Name: Quaternary Science Reviews # Volume: 39 # Edition: # Issue: # Pages: 14-25 # Report_Number: # DOI: # Publication_Place: # Publisher: # ISBN: # Online_Resource: # Other_Reference_Details: # Full_Citation: # Abstract: Iceland is well situated to monitor North Atlantic Holocene climate variability. Terrestrial sites there offer the potential for well-dated, high-resolution, continuous records of environmental change and/or glacier activity. Laminated sediments from the proglacial lake Hvítárvatn provide a continuous record of environmental change and the development of the adjacent Langjökull ice cap for the past 10.2 ka. Replicate lake sediment cores, collected from multiple locations in the basin, are placed in a secure geochronology by splicing a varve chronology for the past 3 ka with a tephra-constrained, paleomagnetic secular variation derived chronology for older sediments. Multiple proxies, including sedimentation rate, bulk density, ice-rafted debris, sediment organic matter, biogenic silica, and diatom abundance, allow annual to multi-decadal resolution and reveal a dynamic Holocene terrestrial climate. Following regional deglaciation of the main Iceland Ice Sheet, summer temperatures were high enough that mountain ice caps had already melted, or were contributing insignificant sediment to the lake. Pronounced increases in sedimentation rate, sediment density, and the influx of terrestrial organic matter, between 8.7 and 7.9 ka suggest early Holocene warmth was interrupted by two distinct pulses of cold summers leading to widespread landscape destabilization and possibly glacier growth. The Holocene thermal maximum (HTM; 7.9 to 5.5 ka) was characterized by high within-lake productivity and ice-free conditions in the watershed. Neoglaciation is recorded as a non-linear transition toward cooler summers, landscape destabilization, and the inception and expansion of Langjökull beginning ca 5.5 ka, with notable increases in ice cap size and landscape instability at 4.2 and 3.0 ka. The past two millennia are characterized by the abrupt onset of sustained cold periods at ca 550 and 1250 AD, separated by an interval of relative warmth from ca 950 to 1150 AD. The greatest Holocene extent of Langjökull occurred in the nineteenth century and is coincident with peak landscape instability, followed by ice recession throughout the twentieth century. #------------------ # Funding_Agency # Funding_Agency_Name: # Grant: #------------------ # Site_Information # Site_Name: Lake Hvítárvatn03-1 # Location: Iceland # Region: central highlands of Iceland # Country: Iceland # Northernmost_Latitude: 64.641944 # Southernmost_Latitude: 64.641944 # Easternmost_Longitude: -19.840278 # Westernmost_Longitude: -19.840278 # Elevation: 422 m #------------------ # Data_Collection # Collection_Name: HVT varve psv # Earliest_Year: 10250 # Most_Recent_Year: -50 # Time_Unit: # Core_Length: # Notes: The sedimentation rate is the average of the combined varve and paleo secular variation of the two cores sites: HVT03-1 and HVT03-2. #------------------ # Species: #------------------ # Chronology: #---------------- # Variables # Short_name What,Material,Error,Units, Seasonality,Archive,Details,Method,Data_type age_BP Age,,,,cal yr bp,,,,Varve counting and paleomagnetic secular variation,N sed_rate Sedimentation rate,,,cm/yr,,paleolimnology,,,N #---------------- # Data # Missing_Values: # # Data line format - tab-delimited text, variable short name as header age_BP sed_rate -50 1.098 0 1.423 50 1.33 100 1.098 150 0.681 200 0.494 250 0.446 300 0.464 350 0.484 400 0.608 450 0.582 500 0.525 550 0.408 600 0.374 650 0.322 700 0.302 750 0.28 800 0.248 850 0.268 900 0.258 950 0.307 1000 0.339 1050 0.353 1100 0.305 1150 0.316 1200 0.294 1250 0.287 1300 0.292 1350 0.23 1400 0.24 1450 0.272 1500 0.258 1550 0.269 1600 0.311 1650 0.282 1700 0.283 1750 0.245 1800 0.264 1850 0.276 1900 0.26 1950 0.262 2000 0.272 2050 0.313 2100 0.264 2150 0.263 2200 0.268 2250 0.292 2300 0.288 2350 0.32 2400 0.282 2450 0.288 2500 0.303 2550 0.265 2600 0.267 2650 0.281 2700 0.289 2750 0.264 2800 0.345 2850 0.352 2900 0.282 2950 0.19 3000 0.12 3050 0.128 3100 0.128 3150 0.136 3200 0.14 3250 0.144 3300 0.148 3350 0.148 3400 0.132 3450 0.084 3500 0.048 3550 0.15 3600 0.166 3650 0.194 3700 0.18 3750 0.164 3800 0.14 3850 0.134 3900 0.14 3950 0.144 4000 0.15 4050 0.146 4100 0.15 4150 0.324 4200 0.216 4250 0.048 4300 0.07 4350 0.08 4400 0.084 4450 0.088 4500 0.096 4550 0.096 4600 0.096 4650 0.088 4700 0.084 4750 0.076 4800 0.074 4850 0.074 4900 0.058 4950 0.054 5000 0.05 5050 0.05 5100 0.05 5150 0.05 5200 0.05 5250 0.05 5300 0.05 5350 0.05 5400 0.048 5450 0.048 5500 0.048 5550 0.046 5600 0.046 5650 0.048 5700 0.046 5750 0.046 5800 0.05 5850 0.052 5900 0.05 5950 0.05 6000 0.048 6050 0.048 6100 0.044 6150 0.042 6200 0.04 6250 0.038 6300 0.04 6350 0.034 6400 0.036 6450 0.034 6500 0.034 6550 0.034 6600 0.032 6650 0.034 6700 0.032 6750 0.034 6800 0.032 6850 0.032 6900 0.032 6950 0.02 7000 0.014 7050 0.01 7100 0.008 7150 0.01 7200 0.01 7250 0.01 7300 0.012 7350 0.012 7400 0.01 7450 0.012 7500 0.012 7550 0.012 7600 0.012 7650 0.012 7700 0.01 7750 0.012 7800 0.018 7850 0.026 7900 0.028 7950 0.068 8000 0.116 8050 0.262 8100 0.322 8150 0.268 8200 0.246 8250 0.188 8300 0.138 8350 0.112 8400 0.07 8450 0.044 8500 0.038 8550 0.042 8600 0.044 8650 0.048 8700 0.048 8750 0.05 8800 0.048 8850 0.05 8900 0.048 8950 0.048 9000 0.05 9050 0.048 9100 0.05 9150 0.048 9200 0.05 9250 0.048 9300 0.05 9350 0.048 9400 0.05 9450 0.048 9500 0.05 9550 0.048 9600 0.05 9650 0.048 9700 0.048 9750 0.05 9800 0.048 9850 0.05 9900 0.048 9950 0.05 10000 0.048 10050 0.05 10100 0.048 10150 0.44 10200 0.46 10250