5. Glaciers#

Note

The Randolph Glacier Inventory is a global inventaroy of glacier outlines. This is cool!!! You could play around it.

Glacier types#

  • Alpine glaciers

  • Continental ice sheets

Climate conditions for glaciers#

  • High snowfall in winter + cool temperature in summer

  • Accumulated snow transforms into firn and then ice

  • In polar and alpine regions

  • Sources and losses

Locations of glaciers#

../_images/global_map_glaciers_tmp1.jpeg

Fig. 9 First-order regions of the RGI version 7.0 and glacier locations in red. Soirce: RGI#

../_images/global_glacier_map_term_type.jpeg

Fig. 10 Terminus type of global glaciers. Soirce: RGI#

The life cycle of a glacier#

  • Snow -> granular ice -> firn -> glacial ice

  • Zones of accumulation and ablation

  • Glaciers in Alaska

../_images/glacier_mass_balance_tmp1.png

Fig. 11 Glacier mass balance and atmospheric circulation. By NASA. From Wikimedia Commons.#

Moraines#

../_images/moraine_tmp1.jpg

Fig. 12 A moraine is an accumulation of loose (unconsolidated) debris – dirt and pieces of rock – that is carried along by a glacier and deposited at some point during the glacier’s journey. Source: here#

Glacier observations and modelling#

Ice shelves and ice bergs#

../_images/ice_shelves_tmp1.jpg

Fig. 13 Source: Arctic Kingdom#

Glacier retreat and sea level rise#

../_images/glacier_retreat.jpeg

Fig. 14 The retreat of Breiðamerkurjökull and growth of Jökulsárlón glacial lake. Source: Glaciological Group of the Institute of Earth Sciences of University of Iceland.#

../_images/glaciers_slr.jpeg

Fig. 15 Global sea level rise. Source: Björnsson et al. (2018)#

Greenland glacier and natural variability#

../_images/glacier_atm_tmp1.jpg

Fig. 16 (a) Time series of June–August (JJA) melt (mm water equivalent [mmWE]/month; dashed line) from the Modèle Atmosphérique Régional simulation and June–August near-surface temperature at 2-m height (T2m; °C; solid line) from ERA-Interim reanalysis averaged over Greenland for 1979–2015, with red dots indicating summers with extreme melt, defined as those with T2m in the top decile. JJA composite anomalies for top decile melt summers relative to the 1980–2009 mean for (b) melt (mmWE/month) and (c) Z500 (m). Stippling indicates anomalies statistically significant at the 95% confidence level. Figure from Hahn et al. (2018)#

Literature review#

Sources#