The Link Between Upper-Slope Submarine Landslides and Mass Transport Deposits in the Hadal Trenchs

Usami, Kazuko; Ikehara, Ken; Kanamatsu, Toshiya; Kioka, Arata; Schwestermann, Tobias; Strasser, Michael

doi:10.1007/978-3-030-60196-6_26

Cited by 8 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Material sorting, reoccurring deposition‐loops, sediment compaction, and complex mixing of different sediment sources during an event is, however, expected to result in some variability around the mean 210 Pb ex concentration in a deposit. The redeposited sediment layers are often associated with abnormal distribution of organic material where older deposits overlay younger material (Bao et al., 2018; Ikehara et al., 2020; Schwestermann et al., 2021; Usami et al., 2021; Xu et al., 2021). However, such events may not only redeposit relic or refractory organic carbon from the slopes toward the trench axes (Kioka et al., 2019a) but may also carry, and focus, relatively fresh phytodetrital material (Oguri et al., 2013) and carrion killed during these catastrophic events (Arai et al., 2013; Oguri et al., 2013).…”

Section: Introductionmentioning

confidence: 99%

Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

et al. 2022

View full text Add to dashboard Cite

Hadal trenches are considered to act as depocenters for organic material, although pathways for the material transport and deposition rates are poorly constrained. Here we assess focusing, deposition and accumulation of material and organic carbon in four hadal trench systems underlying different surface ocean productivities; the eutrophic Atacama and Kuril-Kamchatka trenches, the mesotrophic Kermadec trench and the oligotrophic Mariana Trench. The study is based on the distributions of naturally occurring 210 Pb ex , 137 Cs and total organic carbon from recovered sediment cores and by applying previously quantified benthic mineralization rates. Periods of steady deposition and discreet mass-wasting deposits were identified from the profiles and the latter were associated with historic recorded seismic events in the respective regions. During periods without mass wasting, the estimated focusing factors along trench axes were elevated, suggesting more or less continuous downslope focusing of material toward the interior of the trenches. The estimated organic carbon deposition rates during these periods exhibited extensive site-specific variability, but were generally similar to values encountered at much shallower settings such as continental slopes and margins. Organic carbon deposition rates during periods of steady deposition were not mirrored by surface ocean productivity, but appeared confounded by local bathymetry. The inclusion of deposition mediated by mass-wasting events enhanced the sediment and organic carbon accumulations for the past ∼150 years by up to a factor of ∼4. Thus, due to intensified downslope material focusing and infrequent mass-wasting events, hadal trenches are important sites for deposition and sequestration of organic carbon in the deep sea.Plain Language Summary Hadal trenches (>6,000 m water depth) occupy ∼1% of the world's ocean floor yet are largely underexplored, but recent studies have shown that these environments are depocenters for organic material and microbial activity is intensified when compared to shallower abyssal plains. However, transport and accumulation of sediment material to these hadal trenches is poorly understood. This study investigates sedimentation and accumulation dynamics of organic carbon in trenches using results of radionuclide analysis (in sediment from the Atacama, Kuril-Kamchatka, Kermadec, and Mariana trenches). The analysis shows that trench sediments consist of discreet layers representing both periods of continuous deposition and sudden mass-wasting events often triggered by historic earthquakes. Down slope focusing of material, intensified the deposition along the trench axes. However, the deposition rates exhibited extensive site-specific variations that were partly related to mass-wasting events which greatly enhanced not only mass accumulation but also organic carbon accumulation at the trench axes. Our results illustrate that mass-wasting events play an important role on supplying organic carbon to hadal communities and suggest that hadal tr...

show abstract

Section: Introductionmentioning

confidence: 99%

Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Validity of assignment of PSV correlation has been inspected using OC 14 C (Table 3). Although it has been reported that OC 14 C in hemipelagite is significantly older than those of depositional age in the Japan Trench due to the mixing of old organic matter, the linear relationship between age and depth suggests a possible deposition age with consideration of a age offset (Ikehara et al 2016;Bao et al 2018;Kioka et al 2019;Schwestermann et al 2021;Usami et al 2021). We estimated the offset of OC 14 C using a hemipelagite samples at 13 cm below the Hr-FP (sample KS1416 PC07 sec6-15 in Table 3), which is to be 170 years older than the Hr-FP horizon based on its sedimentation rate.…”

Section: Accuracy and Uncertainty Of Psv Datingmentioning

confidence: 96%

Submarine paleoseismology in the Japan Trench of northeastern Japan: turbidite stratigraphy and sedimentology using paleomagnetic and rock magnetic analyses

Kanamatsu

Ikehara

Hsiung

2023

Prog Earth Planet Sci

Self Cite

View full text Add to dashboard Cite

Previous studies of sediments recovered from the Japan Trench between 37° 25′ N and 38° 30′ N document distinctive turbidite beds induced by huge earthquakes. We studied two sediment cores at 39°N to investigate the depositional record further north along the Japan Trench. These investigations spatially extend our knowledge of the depositional record of earthquakes in the Japan Trench. We examined specifically the precise stratigraphy of turbidite beds using paleomagnetic secular variation, and a tephra correlation. Additionally, anisotropy of magnetic susceptibility (AMS) was investigated to understand the depositional conditions of each turbidite bed. The inferred ages of turbidite beds in this study closely approximate their previously reported ages, which are correlated with the historical and prehistorical huge earthquakes off Tohoku, northeastern Japan. The paleo current directions during deposition of turbidite are inferred from their grain alignment based on AMS data. The directions of basal part reveal northeastward in the slope-side basin and north-northeast in oceanward basin. The directions of basal and upper thick muddy part of a turbidite bed are not always consistent, which suggests the hydraulic condition in the narrow elongated deep-sea basin. This fact could be essential information to elucidate a unique hydraulic condition during the turbidite deposition in the confined basin in the Japan Trench.

show abstract

“…Well-preserved benthic foraminifers were observed in the MTD in some holes. These MTDs were described and dated to 1.77 (+0.49/−0.31) bulk OC 14 C ky before present (BP) by Usami et al (2021) and Schwestermann et al (2021), respectively, although they reported only the upper (muddy) part of the MTD. Similar lithofacies was also found in the lower part of the cores at Sites M0084 and M0088, indicating the repeated occurrence of the MTD in the northern Japan Trench basins.…”

Section: Sediment Lithology and Event Deposits In The Trench-fill Dep...mentioning

confidence: 99%

Expedition 386 Preliminary Report: Japan Trench Paleoseismology

Ikehara,

Strasser,

Everest

et al. 2023

International Ocean Discovery Program Preliminary Report

View full text Add to dashboard Cite

Short historical and even shorter instrumental records limit our perspective of earthquake maximum magnitude and recurrence and thus are inadequate to fully characterize Earth's complex and multiscale seismic behavior and its consequences. Motivated by the mission to fill the gap in longterm paleoseismic records of giant (Mw 9 class) subduction zone earthquakes, such as the Tohoku-Oki earthquake in 2011, International Ocean Discovery Program Expedition 386 successfully collected 29 giant piston cores at 15 sites (total core recovery = 831.19 m), recovering up to 37.82 m long, continuous, upper Pleistocene to Holocene stratigraphic successions of 11 individual trench-fill basins that are expected to have recorded past earthquakes. Preliminary expedition results document event-stratigraphic successions comprising numerous event deposits and initially characterize their different types, facies, properties, composition, and frequency of occurrence, which show spatial variations across the southern, central, and northern Japan Trench.The occurrence of several tephra beds, radiolarian biostratigraphic events, and characteristic variations of paleomagnetic declination and inclination that probably represent paleomagnetic secular variation reveal high potential for establishing robust age models in all parts of the Japan Trench. The central Japan Trench models are most likely to cover the longest timescales, with expected age ranges reaching back to ~24 ka. Together, these preliminary initial results indicate that the applied concept and strategy of multisite coring will likely be successful to test and further develop submarine paleoseismology to extract megathrust earthquake signals from event-stratigraphic sequences preserved in the sedimentary record. Obtained data and samples will now be examined using postexpedition multimethod applications to comprehensively characterize and date event deposits. Detailed work will include detailed characterization of the sedimentologic, physical, and (bio-)geochemical features; stratigraphic expressions of relationships; and spatiotemporal distribution of event beds. These will be analyzed as foundational proxy evidence for distinguishing giant earthquakes from smaller earthquakes and aseismic processes driving mechanisms to ultimately develop a long-term record of giant earthquakes. Furthermore, Expedition 386 achievements comprise the first ever high temporal and high spatial resolution subsurface investigation and sampling in a hadal oceanic trench, which are the deepest and least explored environments on our planet. Preliminary initial results show high total organic carbon content and downcore pore water and headspace gas profiles with characteristic changes related to organic matter degradation. In combination, these are suggestive of the occurrence of intensive remineralization and reveal evidence of non-steady state behavior. Together with the successful offshore sampling for microbiology postexpedition analyses and research, this provides exciting new perspectives to adva...

show abstract

The Link Between Upper-Slope Submarine Landslides and Mass Transport Deposits in the Hadal Trenchs

Cited by 8 publications

References 22 publications

Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

Submarine paleoseismology in the Japan Trench of northeastern Japan: turbidite stratigraphy and sedimentology using paleomagnetic and rock magnetic analyses

Expedition 386 Preliminary Report: Japan Trench Paleoseismology

Contact Info

Product

Resources

About