Numerical studies of Jökulhlaups

摘要: Abstract The aim of this paper is to investigate Jokulhlaups: outbursts ice-dammed lakes. governing equations unsteady water flow through straight, circular conduits, as derived by the authors in a previous paper, are compared with Nye, and for steady state situation Rothlisberger's theory. dynamic theory treated numerically finite-difference technique. Run-off simulations illustrated model Grimsvotn Jokulhlaup, periodic outburst subglacial lake beneath Vatnajokull Iceland. We study how various parameters, such friction coefficient conduit, constants law ice, influence evolution outburst. In particular, we compute discharge hydrographs both incorporating neglecting rate change internal energy. It shown that term not negligible temperature, boundary condition, strongly influences time-discharge relation might explain abrupt end well before has been emptied.