Skip to main content

Buoyancy-driven lacustrine calving, Glaciar Nef, Chilean Patagonia

Buy Article:

$35.11 plus tax (Refund Policy)


Glaciar Nef, a 164 km2eastern outlet of Hielo Patagónico Norte (the northern Patagonia icefield), terminates in a proglacial lake that has formed in conjunction with 20th-century glacier retreat. The terminus is inferred to be transiently afloat. A hinge-calving mechanism is proposed in which buoyant forces impose a torque on the glacier tongue, resulting in the release of coherent sections of the glacier tongue as "tabular" ice-bergs. A simple model shows how torque and tensile stress reach a maximum at the up-glacier limit of the buoyant zone, and that glacier thinning causes this point to migrate up-glacier. Empirical evidence supporting this model includes elevated thermo-erosional notches ≤6.5 m above lake level, and the ubiquitous presence since 1975 of "tabular" ice- bergs with surface areas ≤0.3 km2. Flow speeds of 1.2−1.3 m d−1 were measured near the terminus in February 1998. Extrapolations from these short-term data yield a calvingrate of 785−835 m a−1 and a calvingflux of 232 × 106 m3 a−1 or 0.2 km3 a−1. The calculated mean water depth at the terminus is 190 m. This calvingrate is higher than at grounded temperate glaciers calving in fresh water, but is nevertheless almost an order of magnitude less than calvingrates at both grounded and floatingtidewater glaciers.

Document Type: Research Article


Publication date: January 1, 2001

More about this publication?
  • The Journal of Glaciology is published six times per year. It accepts submissions from any discipline related to the study of snow and ice. All articles are peer reviewed. The Journal is included in the ISI Science Citation Index.
  • Editorial Board
  • Information for Authors
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more