A national glacier inventory and variations in glacier extent in Iceland from the Little Ice Age maximum to 2019

JOKULL ◽  
2020 ◽  
Vol 70 ◽  
pp. 1-34
Author(s):  
Hrafnhildur Hannesdóttir ◽  
Oddur Sigurðsson ◽  
Ragnar Þrastarson ◽  
Snævarr Guðmundsson ◽  
Joaquín Belart ◽  
...  

Abstract — A national glacier outline inventory for several different times since the end of the Little Ice Age (LIA) in Iceland has been created with input from several research groups and institutions, and submitted to the GLIMS (Global Land Ice Measurements from Space, nsidc.org/glims) database, where it is openly available. The glacier outlines have been revised and updated for consistency and the most representative outline chosen. The maximum glacier extent during the LIA was not reached simultaneously in Iceland, but many glaciers started retreating from their outermost LIA moraines around 1890. The total area of glaciers in Iceland in 2019 was approximately 10,400 km2, and has decreased by more than 2200 km2 since the end of the 19th century (corresponding to an 18% loss in area) and by approximately 750 km2 since ~2000. The larger ice caps have lost 10–30% of their maximum LIA area, whereas intermediate-size glaciers have been reduced by up to 80%. During the first two decades of the 21st century, the decrease rate has on average been approximately 40 km2 a-1. During this period, some tens of small glaciers have disappeared entirely. Temporal glacier inventories are important for climate change studies, for calibration of glacier models, for studies of glacier surges and glacier dynamics, and they are essential for better understanding of the state of glaciers. Although surges, volcanic eruptions and jökulhlaups influence the position of some glacier termini, glacier variations have been rather synchronous in Iceland, largely following climatic variations since the end of the 19th century.

1996 ◽  
Vol 22 ◽  
pp. 181-186 ◽  
Author(s):  
W.B. Whalley ◽  
C.F. Palmer ◽  
S.J. Hamilton ◽  
D. Kitchen

The volume of debris in the left-lateral, Little Ice Age (LIA:AD1550–1850) moraine of the Feegletscher, Valais, Switzerland was compared with the actual volume being transported currently by the glacier. The latter is smaller by a factor of about two. In Tröllaskagi, north Iceland, a surface cover of debris on top of a very slow moving glacier ice mass (glacier noir, rock glacier) has been dated by lichenometry. The age of the oldest part is commensurate with LIA moraines in the area. Knowing the volume of debris of a given age allows an estimate of the debris supply to the glacier in a given time. Again, there appears to have been a significant reduction in debris to the glacier since the turn of the 19th century. Debris input in the early LIA seems to have been particularly copious and this may be important in the formation of some glacier depositional forms such as rock glaciers.


1999 ◽  
Vol 28 ◽  
pp. 123-128 ◽  
Author(s):  
Manuela Pelfini

AbstractIn the Italian Alps, the maximum advance of the Holocene usually coincided with the Little Ice Age (LIA), which reached a climax for most glaciers during the first two decades of the 19th century. Moraines deposited during the peak of the LIA usually obliterated glacial deposits from previous advances. Using dendrogeomorphology, it is possible to date glacier advances before the LIA peak. In the central Italian Alps, it was possible to pinpoint an advance of Ghiacciaio del Madaccio, which took place in the first two decades of the 17th century. With dendrogeomorphology, it is also possible to reconstruct in detail the behaviour of glaciers during the Little Ice Age climax. Trees growing on the margin of glacier tongues may have suffered damage, recognizable by the presence of wood scars and the formation of particularly thin rings; their dating allows both ice advances and retreats to be dated. This is the case for Ghiacciaio Grande di Verra in the western Italian Alps; owing to the rapid decrease of the tree ring widths, it is possible to recognize climate changes responsible for both lower wood production and, sometimes, subsequent glacier advances, although the latter take place with a certain delay. For Ghiacciaio del Lys in the western Italian Alps, a response time of five years was determined.


1995 ◽  
Vol 32 (5) ◽  
pp. 579-589 ◽  
Author(s):  
Daniel J. Smith ◽  
Daniel P. Mccarthy ◽  
Margaret E. Colenutt

Dendrochronological, lichenometric, and 14C studies at 14 glacier sites in Peter Lougheed and Elk Lakes provincial parks were used to develop a chronology of Little Ice Age glacial events. The earliest indications of glacial activity are represented by moraines deposited prior to the 16th century. A major glacial expansion in the 17th century is recorded at three sites, where I4C dates show glaciers reached their maximum down-valley positions. Lichenometric dates and tree growth suppression records show a phase of glacial activity early in the 18th century, for which there is only sparse morainic evidence. Most moraines in the area date from a glacial advance culminating in the mid-19th century, and moraine formation was complete everywhere by the late 1800's. Recessional moraines are rare in the study area and indicate that ice-front retreat has been relatively continuous since the 19th century. The glacial chronology developed in this work is comparable to that reconstructed for both the Main Ranges of the Canadian Rockies and the Coast Ranges of the southern Cordillera.


1996 ◽  
Vol 22 ◽  
pp. 181-186 ◽  
Author(s):  
W.B. Whalley ◽  
C.F. Palmer ◽  
S.J. Hamilton ◽  
D. Kitchen

The volume of debris in the left-lateral, Little Ice Age (LIA: AD 1550–1850) moraine of the Feegletscher, Valais, Switzerland was compared with the actual volume being transported currently by the glacier. The latter is smaller by a factor of about two. In Tröllaskagi, north Iceland, a surface cover of debris on top of a very slow moving glacier ice mass (glacier noir, rock glacier) has been dated by lichenometry. The age of the oldest part is commensurate with LIA moraines in the area. Knowing the volume of debris of a given age allows an estimate of the debris supply to the glacier in a given time. Again, there appears to have been a significant reduction in debris to the glacier since the turn of the 19th century. Debris input in the early LIA seems to have been particularly copious and this may be important in the formation of some glacier depositional forms such as rock glaciers.


The Holocene ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Ioana Perșoiu ◽  
Aurel Perșoiu

We present here the first record of past flooding activity from the Carpathian Mountains, Eastern Europe, based on documentary evidence and sedimentary records along one of the main rivers draining this region (Someșul Mic River). Three periods of increased flood activity have occurred in Transylvania during the last millennium: the first at the beginning of the 10th century (the end of the Dark Ages Cold Period and beginning of the Medieval Warm Period (MWP)); the second at the end of the 16th and beginning of 17th century, during the cold Little Ice Age (LIA) and the third at the end of the 19th century. During the early MWP, generally wet summers resulted in a high incidence of floods and/or high discharges, while the cluster of floods at the end of 16th and beginning of the 17th centuries occurred mostly at flash floods generated during heavy summer thunderstorms. Increasing winter temperatures and spring precipitations probably caused the high incidence of floods at the end of the 19th century. The predominantly wet conditions during the MWP are likely to have resulted from northward penetration of Mediterranean cyclones during a (mostly) positive phase of the North Atlantic Oscillation (NAO), while wet conditions during the LIA arose as a combination of increases in local storminess and moisture transport from the North Atlantic along more southerly positioned westerlies associated with a negative phase of the NAO.


2009 ◽  
Vol 50 (53) ◽  
pp. 11-21 ◽  
Author(s):  
Felix Svoboda ◽  
Frank Paul

AbstractThe quantitative assessment of glacier changes as well as improved modeling of climate-change impacts on glaciers requires digital vector outlines of individual glacier entities. Unfortunately, such a glacier inventory is still lacking in many remote but extensively glacierized gions such as the Canadian Arctic. Multispectral satellite data in combination with digital elevation models (DEMs) a particularly useful for creating detailed glacier inventory data including topographic information for each entity. In this study, we extracted glacier outlines and a DEM using two adjacent Terra ASTER scenes acquired in August 2000 for a remote region on southern Baffin Island, Canada. Additionally, Little Ice Age (LIA) extents we digitized from trimlines and moraines visible on the ASTER scenes, and Landsat MSS and TM scenes from the years 1975 and 1990 we used to assess changes in glacier length and area. Because automated delineation of glaciers is based on a band in the shortwave infrared, we have developed a new semi-automated glacier-mapping approach for the MSS sensor. Wrongly classified debris-coved glaciers, water bodies and attached snowfields we corrected manually for both ASTER and MSS. Glacier drainage divides we manually digitized by combining visual interptation with DEM information. In this first paper, we describe the applied methods for glacier mapping and the glaciological challenges encounted (e.g. data voids, snow cover, ice caps, tributaries), while the second paper ports the data analyses and the derived changes.


2018 ◽  
Vol 6 ◽  
Author(s):  
Wolfgang J.-H. Meier ◽  
Jussi Grießinger ◽  
Philipp Hochreuther ◽  
Matthias H. Braun

2007 ◽  
Vol 46 ◽  
pp. 145-149 ◽  
Author(s):  
Andreas Bauder ◽  
Martin Funk ◽  
Matthias Huss

AbstractThe evolution of surface topography of glaciers in the Swiss Alps is well documented with high-resolution aerial photographs repeatedly recorded since the 1960s and further back in time with topographic maps including elevation contour lines first surveyed in the mid-19th century. In order to quantify and interpret glacier changes in the Swiss Alps, time series of volume changes over the last 100–150 years have been collected. The available datasets provide a detailed spatial resolution for the retreat period since the end of the Little Ice Age. The spatial distribution as well as temporal variations of the thickness change were analyzed. A significant ice loss since the end of the 19th century was observed in the ablation area, while the changes in the accumulation area were small. We found moderate negative secular rates until the 1960s, followed by steady to positive rates for about two decades and strong ice loss starting in the 1980s which has lasted until the present. An evaluation of 19 glaciers revealed a total ice volume loss of about 13km3 since the 1870s, of which 8.7 km3 occurred since the 1920s and 3.5 km3 since 1980. Decadal mean net balance rates for the periods 1920–60, 1960–80 and 1980–present are –0.29, –0.03 and –0.53ma–1w.e., respectively.


2014 ◽  
Vol 55 (66) ◽  
pp. 167-176 ◽  
Author(s):  
E.Yu. Osipov ◽  
O.P. Osipova

AbstractContemporary glaciers of southeast Siberia are located on three high-mountain ridges (east Sayan, Baikalsky and Kodar). In this study, we present an updated glacier inventory based on high- to middle-resolution satellite imagery and field investigations. The inventory includes 51 glaciers with a total area of - 15 km2. Areas of individual glaciers vary from 0.06 to 1.33 km2, lengths from 130 to 2010 m and elevations from 1796 to 3490 m. The recent ice maximum extents (Little Ice Age) have been delineated from terminal moraines. On average, debris-free surface area shrunk by 59% between 1850 and 2006/11 (0.37% a–1), by 44% between 1850 and 2001/02 (0.29% a–1) and by 27% between 2001/02 and 2006/11 (3.39% a–1). The Kodar glaciers have experienced the largest area shrinkage, while the area loss on Baikalsky ridge was more moderate. Glacier changes are mainly related to regional summer temperature increase (by 1.7-2.6C from 1970 to 2010). There are some differences in glacier response due to different spatial patterns of snow accumulation, local topography (e.g. glacier elevation, slope) and geological activity. The studied glaciers (especially of Kodar ridge) are the most sensitive in Siberia to climate change since the late 20th century.


1986 ◽  
Vol 26 (1) ◽  
pp. 27-48 ◽  
Author(s):  
Stephen C. Porter

Time series depicting mountain glacier fluctuations in the Alps display generally similar patterns over the last two centuries, as do chronologies of glacier variations for the same interval from elsewhere in the Northern Hemisphere. Episodes of glacier advance consistently are associated with intervals of high average volcanic aerosol production, as inferred from acidity variations in a Greenland ice core. Advances occur whenever acidity levels rise sharply from background values to reach concentrations ≥1.2 μequiv H+/kg above background. A phase lag of about 10–15 yr, equivalent to reported response lags of Alpine glacier termini, separates the beginning of acidity increases from the beginning of subsequent ice advances. A similar relationship, but based on limited and less-reliable historical data and on lichenometric ages, is found for the preceding 2 centuries. Calibrated radiocarbon dates related to advances of non-calving and non-surging glaciers during the earlier part of the Little Ice Age display a comparable consistent pattern. An interval of reduced acidity values between about 1090 and 1230 A.D. correlates with a time of inferred glacier contraction during the Medieval Optimum. The observed close relation between Noothern Hemisphere glacier fluctuations and variations in Greenland ice-core acidity suggests that sulfur-rich aerosols generated by volcanic eruptions are a primary forcing mechanism of glacier fluctuations, and therefore of climate, on a decadal scale. The amount of surface cooling attributable to individual large eruptions or to episodes of eruptions is simlar to the probable average temperature reduction during culminations of Little Ice Age alacier advances (ca. 0.5°–1.2°C), as inferred from depression of equilibrium-line altitudes.


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