Title of article :
Discussion of ‘Field evidence and hydraulic modeling of a large Holocene jökulhlaup at Jökulsá á Fjöllum channel, Iceland’ by Douglas Howard, Sheryl Luzzadder-Beach and Timothy Beach, 2012
Carrivick، نويسنده , , Jonathan L. and Tweed، نويسنده , , Fiona S. and Carling، نويسنده , , Paul and Alho، نويسنده , , Petteri and Marren، نويسنده , , Philip M. and Staines، نويسنده , , Kate and Russell، نويسنده , , Andrew J. and Rushmer، نويسنده , , E. Lucy and Duller، نويسنده , , Robert، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
This paper discusses Howard et al. (2012) who reconstruct the peak discharge of a glacial outburst flood, or ‘jökulhlaup’, for part of the Jökulsá á Fjöllum in north-central Iceland. They propose that this flood was the largest on Earth. We consider that the magnitude of the jökulhlaup proposed by Howard et al. (2012) warrants much more robust field evidence and demands more carefully parameterised hydraulic modelling. For these reasons we firstly (i) present their study in the context of previous research (ii) highlight issues with attributing landforms and sediments to jökulhlaups, and (iii) consider uncertainty regarding the timing and magnitude of jökulhlaups along the Jökulsá á Fjöllum. We argue herein that whilst a range of landforms and sediments that are attributable to jökulhlaups can be observed along the Jökulsá á Fjöllum, these are not necessarily diagnostic of jökulhlaups. Secondly, we critically discuss (iv) the major underlying assumptions of their study, and (v) their calculations and subsequent interpretations. These assessments lead us to consider that the proposal by Howard et al. (2012) of the largest flood on Earth is highly unrealistic, especially when due consideration is given to a possible source area and a trigger mechanism.
Iceland , Jِkulsل ل Fjِllum , Outburst flood , Landscape , Hydraulics
Journal title :