Jökulhlaup: Difference between revisions

Since jökulhlaups emerge from [[hydrostatic]]ally sealed lakes with floating levels far above the threshold, their peak [[discharge (hydrology)|discharge]] can be much larger than that of a marginal or extra-marginal lake burst. The [[hydrograph]] of a jökulhlaup from Vatnajökull typically either climbs over a period of weeks with the largest flow near the end, or it climbs much faster during the course of some hours. These patterns are suggested to reflect channel melting, and sheet flow under the front, respectively.<ref name=helgi>{{cite journal|last=Björnsson|first=Helgi|title=Subglacial Lakes and Jökulhlaups in Iceland|journal=Global and Planetary Change|year=2002|volume=35|issue=3–4|pages=255–271|url=http://www.norvol.hi.is/pdf/HB2003GlobPlanCh.pdf|doi=10.1016/s0921-8181(02)00130-3|bibcode=2003GPC....35..255B|access-date=8 March 2013|archive-date=31 July 2021|archive-url=https://web.archive.org/web/20210731062914/http://www.norvol.hi.is/pdf/HB2003GlobPlanCh.pdf|url-status=dead}}</ref> Similar processes on a very large scale occurred during the [[deglaciation]] of North America and Europe after the [[Last glacial period|last ice age]] (e.g., [[Lake Agassiz]] and the [[English Channel]]), and presumably at earlier times, although the geological record is not well preserved.

 

 

===Subglacial water generation===