Abstract Lake sediments in Eklutna Lake, Alaska, reveal the presence of turbidites within varved sequences. These turbidites, which result from flood events and earthquakes, show a similar macroscopic appearance. In order to use reconstruct variability and/or seismic history lake basin, it is crucial determine trigger turbidity currents. This study examined turbidite caused by ad 1964 Great Alaska earthquake as well linked historical differentiate between these earthquake‐triggered...

ABSTRACT Glass composition‐based correlations of volcanic ash (tephra) traditionally rely on extensive manual plotting. Many previous statistical methods for testing are limited by using geochemical means, masking diagnostic variability. We suggest that machine learning classifiers can expedite correlation, quickly narrowing the list likely candidates well‐trained models. Eruptives from Alaska's Aleutian Arc‐Alaska Peninsula and Wrangell field were used as a test environment 11 supervised...

Abstract Turbidites embedded in lacustrine sediment sequences are commonly used to reconstruct regional flood or earthquake histories. A critical step for this method be successful is that turbidites and their trigger mechanisms determined unambiguously. The latter particularly challenging prehistoric proglacial lake records high‐seismicity settings where both earthquake‐generated flood‐generated interrupt the background varved sedimentation. This calls a new allow efficient objective...

Research Article| November 22, 2017 Varve formation during the past three centuries in large proglacial lakes south-central Alaska Evelien Boes; Boes † 1Renard Centre of Marine Geology, Department Ghent University, Krijgslaan 281, 9000 Ghent, Belgium †evelien.boes@ugent.be; maarten.vandaele@ugent.be; jasper.moernaut@uibk.ac.at; sabine.schmidt@u-bordeaux.fr; nore.praet@ugent.be; darrell.kaufman@nau.edu; pheuslr@usgs.gov; michael_loso@nps.gov; marc.debatist@ugent.be. Search for other works by...

Abstract The 30 November 2018 Mw 7.1 Anchorage earthquake caused modified Mercalli intensities of V¼ to V½ at Eklutna Lake (south central Alaska). A few hours after the earthquake, a “dirt streak” was observed on lake surface, followed by peak in sediment turbidity values (∼80 times normal) drinking water facility, which receives from through pipe. These observations hint toward currents triggered Lake. Here, we study 32 short cores retrieved across and observe millimeter‐to‐centimeter scale...

Abstract Seismic hazards in subduction settings typically arise from megathrust, intraslab and crustal earthquake sources. Despite the frequent occurrence of earthquakes zones their potential threat to communities, long‐term recurrence behaviour is barely studied. Sedimentary sequences lakes may register ground shaking different seismic This study investigates two long sediment cores (13 m 16 m) Skilak Lake, a proglacial lake south‐central Alaska, evaluate whether sources leave distinct...

ABSTRACT Megaturbidites are commonly used to reconstruct the seismic history (palaeoseismology) of areas where large earthquakes occur. However, depositional mechanisms and sedimentary characteristics these deposits not yet fully understood. This study unravels sequence sediment deposition that occurred in Lake Lucerne (Vitznau Basin) following 1601 ce earthquake central Switzerland. During this event, slope failures were triggered, generating mass flows turbidity currents led formation...

Abstract. We describe the Chipalamawamba Beds, early to middle Holocene deposits at southern margin of long-lived Lake Malawi. The beds are exposed because downcutting upper Shire River. sediments medium coarse, yellow brown sands deposited in lenses varying horizontal extent from a few meters several hundreds meters. Four units recognized; first three mainly contain lacustrine during lake high stands about 10.6–9.7 cal ka BP (Unit 1), 7.6–6.5 2) and 5.9–5.3 3). Sediments Unit 4 overlay...

Snow avalanches cause many fatalities every year and damage local economies worldwide. The present-day climate change affects the snowpack and, thus, properties frequency of snow avalanches. Reconstructing avalanche records can help us understand past variations in their relationship to change. Previous have primarily been reconstructed using dendrochronology. Here, we investigate potential lake sediments record by studying 27 < 30-cm-long sediment cores from Kenai Lake, south-central...

Monitoring turbidity is essential for sustainable coastal management because an increase in leading to diminishing water clarity has a detrimental ecological impact. Turbidity waters strongly dependent on the concentration and physical properties of particles column. In Belgian part North Sea, suspended particulate matter (SPM) concentrations have been monitored decades by satellite remote sensing, but this technique only focuses surface layer Within column, SPM are measured stations or...

Sand extraction on the sand banks in Belgian part of North Sea has various impacts marine environment. The direct near-field effects areas where takes place, are regularly monitored for at least two decades and well understood. In contrast, several important questions remain regarding far-field impact associated with dispersion suspended particle matter (SPM) plumes. On longer term, these SPM plumes could significantly change integrity seafloor damage ecological valuable habitats bordering...

Monitoring suspended particulate matter (SPM) in coastal areas is essential for research, management and protection of ecosystems. In the Belgian part North Sea, dynamic nature SPM variability increasing human activities (offshore windmill parks, dredging dumping) call 3D monitoring these natural human-induced changes.Multibeam echosounders (MBES) provide, addition to bathymetry seafloor backscatter data, a dataset acoustic measurements water column, which can be used monitor waters....

Abstract Suspended sediment delivery and deposition in proglacial lakes is generally sensitive to a wide range of hydrometeorologic geomorphic controls. High discharge conditions are particular importance many glaciolacustrine records, with individual floods potentially recorded as distinctive turbidites. We used an extensive network surface cores hydroclimatic monitoring data analyse recent flood turbidites associated transfer controls over instrumental periods at Eklutna Lake, western...

Abstract. We describe the Chipalamawamba Beds, early to middle Holocene deposits at southern margin of long-lived Lake Malawi. The beds are exposed because downcutting upper Shire River. sediments medium coarse, yellow brown sands deposited in lenses varying horizontal extent from a few meters several hundreds meters. Four units recognized; first three mainly contain lacustrine during lake high-stands about 10.6–9.7 cal ka BP (Unit 1), 7.6–6.5 2) and 5.9–5.3 BP. Sediments Unit 4 top 1 3,...

A few powerful tools already exist for processing and investigating multibeam echosounder (MBES) data. They fulfill many industrial scientific needs regarding quick visualization bathymetric processing. However, none of these sufficiently target scientists that need to- develop new or custom MBES methods.Projects focusing on objects in the water column (e.g. gas bubble streams, suspended particulate matter, fish, …) formed base a MEBS tool is currently being developed within...

Turbidity is an essential indicator of the water quality in coastal settings as it influences penetration light waters. Next to natural processes, turbidity influenced by human activities such dredging or bottom-trawling fishing activities. If commonly characterized locally through a range methods (moorings, tripods, ship-based samples, ACDP), dynamic nature requires development 4D monitoring methods. Recent years have seen growth use multibeam echosounder (MBES) characterize column, for...