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| Titel |
Internationally coordinated glacier monitoring – a timeline since 1894 |
| VerfasserIn |
Samuel U. Nussbaumer, Richard Armstrong, Florence Fetterer, Isabelle Gärtner-Roer, Martin Hoelzle, Horst Machguth, Nico Mölg, Frank Paul, Bruce H. Raup, Michael Zemp |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130614
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| Publikation (Nr.) |
 EGU/EGU2016-10891.pdf |
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| Zusammenfassung |
| Changes in glaciers and ice caps provide some of the clearest evidence of climate change,
with impacts on sea-level variations, regional hydrological cycles, and natural hazard
situations. Therefore, glaciers have been recognized as an Essential Climate Variable (ECV).
Internationally coordinated collection and distribution of standardized information about the
state and change of glaciers and ice caps was initiated in 1894 and is today organized within
the Global Terrestrial Network for Glaciers (GTN-G). GTN-G ensures the continuous
development and adaptation of the international strategies to the long-term needs of users in
science and policy. A GTN-G Steering Committee coordinates, supports and advices the
operational bodies responsible for the international glacier monitoring, which are the
World Glacier Monitoring Service (WGMS), the US National Snow and Ice Data
Center (NSIDC), and the Global Land Ice Measurements from Space (GLIMS)
initiative.
In this presentation, we trace the development of the internationally coordinated glacier
monitoring since its beginning in the 19th century. Today, several online databases containing
a wealth of diverse data types with different levels of detail and global coverage provide fast
access to continuously updated information on glacier fluctuation and inventory data. All
glacier datasets are made freely available through the respective operational bodies
within GTN-G, and can be accessed through the GTN-G Global Glacier Browser
(http://www.gtn-g.org/data_browser.html).
Glacier inventory data (e.g., digital outlines) are available for about 180,000 glaciers
(GLIMS database, RGI – Randolph Glacier Inventory, WGI – World Glacier Inventory).
Glacier front variations with about 45,000 entries since the 17th century and about 6,200
glaciological and geodetic mass (volume) change observations dating back to the 19th
century are available in the Fluctuations of Glaciers (FoG) database. These datasets
reveal clear evidence that glacier retreat and mass loss is a global phenomenon.
Glaciological and geodetic observations show that the rates of the 21st-century
mass loss are unprecedented on a global scale, for the time period observed, and
probably also for recorded history, as indicated in glacier reconstructions from
written and illustrated documents. The databases are supplemented by specific
index datasets (e.g., glacier thickness data) and a dataset containing information
on special events including glacier surges, glacier lake outbursts, ice avalanches,
eruptions of ice-clad volcanoes, etc. related to about 200 glaciers. A special database of
glacier photographs (GPC – Glacier Photograph Collection) contains more than
15,000 pictures from around 500 glaciers, some of them dating back to the mid-19th
century.
Current efforts are to close remaining observational gaps regarding data both from in-situ
measurements and remote sensing, to establish a well-distributed baseline for sound estimates
of climate-related glacier changes and their impacts. Within the framework of dedicated
capacity building and twinning activities, disrupted long-term mass balance programmes in
Central Asia have recently been resumed, and the continuation of mass balance
measurements in the Tropical Andes has been supported. New data also emerge from several
research projects using NASA and ESA sensors and are actively integrated into the
GTN-G databases. Key tasks for the future include the quantitative assessment of
uncertainties of available measurements, and their representativeness for changes in
the respective mountain ranges. For this, a well-considered integration of in-situ
measurements, remotely sensed observations, and numerical modelling is required. |
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