Marine sedimentary record of Meltwater Pulse 1a along the NW Barents Sea continental margin

Renata Giulia Lucchi,Angelo Camerlenghi,Giovanna Giorgetti,Leonardo Sagnotti,Maria Teresa Pedrosa,Michele Rebesco,Patrizia Macrì

doi:10.1007/s41063-015-0008-6

Abstract

The upper continental slope of the Storfjorden-Kveithola Trough Mouth Fans (NW Barents Sea) contains a several m-thick late Pleistocene sequence of plumites composed of laminated mud interbedded with sand/silt layers. Radiocarbon ages revealed that deposition occurred during about 130 years at a very high sedimentation rate of 3.4 cm a−1, at about 7 km from the present shelf break. Palaeomagnetic and rock magnetic analyses confirm the existence of a prominent, short-living sedimentary event. The plumites appear laterally continuous and were correlated with the sedimentary sequences described west of Svalbard and neighboring glacial depositional systems representing a major event at regional scale appointed to correspond to the deep-sea sedimentary record of Meltwater Pulse-1a. We also present new sedimentological and geochemical insights, and multi-beam data adding information on the palaeoenvironmental characteristics during MWP-1a and ice sheet decay in the NW Barents Sea.

Highlights

Meltwater Pulse 1aA meltwater pulse (MWP) is a short-lived, global acceleration in sea-level rise resulting from intense front- and/or subglacial meltwater release, and/or surging ice streams into oceans and iceberg discharge during ice sheets disintegration [9]
The sediment cores (Table 1) were logged through an X-ray CT scan and an Avaatech XRF-core scan for chemical composition of the sediments. For this contribution we considered the down-core trends of Si content as proxy of the quartz content rather than amorphous silica forming diatoms frustules; the Cl content was associated with the water content; the Sr content was used as indicator of bio-productivity in place of barium that in the Arctic areas is often of detrital origin; and the S content, commonly associated to oxygen depleted environments
Decay and retreat of the Storfjorden and Kveithola palaeoice streams after the LGM were reconstructed through sedimentological and geochemical analysis of deep-sea marine sediments and new multi-beam and sub-bottom profiler data analysis

Summary

Introduction

A meltwater pulse (MWP) is a short-lived, global acceleration in sea-level rise resulting from intense front- and/or subglacial meltwater release, and/or surging ice streams into oceans and iceberg discharge during ice sheets disintegration [9]. It has been calculated that the rate of global sea-level rise during meltwater pulses could have been as high as 60 mm a-1 during less than 500 years [29]. [4]; and MWP-1c at about 8.000 cal a BP [11, 33] Of these events, MWP-1a was possibly the most prominent leading to a global sea-level rise of about 20 m in the course of 340 a (5.9 cm a-1, [24])

Methods

Discussion

Conclusion