Disestablishing “Glacial Lake Speight”, New Zealand? An example for the validity of detailed geomorphological assessment with the study of mountain glaciations
Detailed studies on the sediment budget may reveal valuable insights into the successive build-up of the Canterbury Plains and their modiﬁcation by Holocene ﬂuvialaction connected to major braided rivers. Additionally, they bear implications beyond these ﬂuvial aspects. Palaeoseismological studies claim to have detected signals of major Alpine Fault earthquakes in coastal environments along the eastern seaboard of the South Island (McFadgen and Goff, 2005). This requires high connectivity between the lower reaches of major braided rivers and their mountain catchments to generate immediate signiﬁcant sediment pulses. It would be contradictory to the above mentioned hypothesis though. Obtaining better control on sediment budgets of braided rivers like the Waimakariri River will ﬁnally add signiﬁcant value to multiple scientiﬁc and applied topics like regional resource management. An essential ﬁrst step of sediment budget studies Is to systematically map the geomorphology, conventionally in the ﬁeld and/or using remote-sensing applications, to localise, genetically identify, and classify landforms or entire toposequences of the area being investigated. In formerly glaciated mountain environments it is also indispensable to obtain all available chronological information supporting subsequent investigations.