Geoscience Reference
In-Depth Information
Glaciers in the Earth's Hydrological Cycle: Assessments
of Glacier Mass and Runoff Changes on Global
and Regional Scales
Valentina Radi
´
Regine Hock
•
Received: 4 May 2013 / Accepted: 29 October 2013 / Published online: 11 December 2013
Springer Science+Business Media Dordrecht 2013
Abstract Changes in mass contained by mountain glaciers and ice caps can modify the
Earth's hydrological cycle on multiple scales. On a global scale, the mass loss from
glaciers contributes to sea-level rise. On regional and local scales, glacier meltwater is an
important contributor to and modulator of river flow. In light of strongly accelerated
worldwide glacier retreat, the associated glacier mass losses raise concerns over the sus-
tainability of water supplies in many parts of the world. Here, we review recent attempts to
quantify glacier mass changes and their effect on river runoff on regional and global scales.
We find that glacier runoff is defined ambiguously in the literature, hampering direct
comparison of findings on the importance of glacier contribution to runoff. Despite con-
sensus on the hydrological implications to be expected from projected future warming,
there is a pressing need for quantifying the associated regional-scale changes in glacier
runoff and responses in different climate regimes.
Keywords Glaciers
Mass balance
Glacier runoff
Sea-level rise
Mass-balance observations
Glacier projections
Modeling
1 Introduction
Mountain glaciers and ice caps, covering 734,400 km
2
on Earth (Gardner et al.
2013
), are
an integral part of the Earth's hydrological cycle affecting water balances on all spatial
