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== Card #19: Melting Ice Sheets == | |||
<center> | |||
== Explanation == | [[File:En-en_adult_card_19_front.png|400px]] | ||
Greenland and Antarctica are ice sheets (or continental glaciers). If they were to completely melt, they will cause the sea level to rise by 7 | |||
metres for Greenland and 54 metres for Antarctica. During the last ice age, ice sheets were so much larger that the sea level was 120 metres lower than today. | |||
</center> | |||
== Explanation== | |||
These illustrations represent the gain or loss of mass of the caps, indicated in centimetres of water per year (cm of water/year) and measured gravimetrically. In blue the mass gain (because it snows more) and in red the losses (glaciers flow faster towards the ocean). | These illustrations represent the gain or loss of mass of the caps, indicated in centimetres of water per year (cm of water/year) and measured gravimetrically. In blue the mass gain (because it snows more) and in red the losses (glaciers flow faster towards the ocean). | ||
== Definition == | == Definition == | ||
An ice cap ( | An ice cap (or ice sheet) is a continental-scale mass of land ice, thick enough (between 1,600 and 6 400 m thick<ref>[https://www.nationalgeographic.org/encyclopedia/ice-sheet/ National Geographic Resource Library]</ref>) that covers most of the underlying rock formations. There are currently only two major ice sheets, one in Greenland and one in Antarctica.<ref>[https://archive.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_SummaryVolume_FINAL_FRENCH.pdf IPCC, 2013: Glossary (Planton, S. (coord.)). P.196. (French)]</ref> | ||
We will speak here of melting of the ice caps when the total mass of ice has decreased over the period under consideration, whatever the processes involved. | We will speak here of melting of the ice caps when the total mass of ice has decreased over the period under consideration, whatever the processes involved. | ||
== Correction== | |||
===Causes=== | |||
* [[En-en_adult_card_14_energy_budget|Energy Budget]] | |||
=== Consequences === | |||
*[[En-en_adult_card_22_sea_level_rise|Rising Sea Levels]] | |||
*[[En-en_adult_card_42_thermohaline_circulation|Thermohaline Circulation]] | |||
== To go further == | == To go further == | ||
=== Numbers === | === Numbers === | ||
Between 2006 and 2015, the loss of ice from the ice caps is : | Between 2006 and 2015, the loss of ice from the ice caps is: | ||
* 278 billion tonnes per year for Greenland | * 278 billion tonnes per year for Greenland | ||
* 155 billion tonnes per year for the Antarctic<ref>[https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/03_SROCC_SPM_FINAL.pdf#page=6 IPCC, Special report on cryosphere and oceans]</ref>. | * 155 billion tonnes per year for the Antarctic<ref>[https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/03_SROCC_SPM_FINAL.pdf#page=6 IPCC, Special report on cryosphere and oceans]</ref>. | ||
For some great graphics that illustrate Earth's ice loss, check out [http://www.esa.int/Applications/Observing_the_Earth/CryoSat/Our_world_is_losing_ice_at_record_rate this article from ESA]. | |||
== References == | == References == | ||
<references /> | <references /> | ||
[[fr:Fr-fr_adulte_carte_19_fonte_des_calottes_glaciaires]] |