 |
| Titel |
Pathways and rates of carbon mineralization on the Eastern Siberian shelf and slope |
| VerfasserIn |
Volker Brüchert, Lisa Bröder, Joanna Sawicka, Jayne Rattray, Örjan Gustafsson, Vladimir Samarkin, Tommaso Tesi |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250135252
|
| Publikation (Nr.) |
 EGU/EGU2016-16096.pdf |
|
|
|
|
|
| Zusammenfassung |
| In recent years the Eastern Siberian Sea shelf and slope have received considerable attention
because the area connects some of the largest landward organic carbon reservoirs on Earth –
Arctic soil and permafrost carbon - with the ocean. Understanding mobilization and
transport of organic carbon along the land-sea continuum and quantifying the burial
efficiency of carbon in the seafloor are critical for quantifying the inventory of marine
dissolved inorganic carbon and the exchange of CO2 with the atmosphere. We report on
biomarker composition, oxygen uptake rates, sulfate reduction rates as well as porewater
chemistry from 18 stations from the Laptev Sea to the Eastern Siberian Sea ranging
from 40 to 3000 m water depth. Our data indicate overall low rates of aerobic and
anaerobic carbon mineralization compared to other shelf and slope marine environments
indicating that the deposited organic material is of overall low reactivity. Carbon
mineralization rates increase eastward towards the Eastern Siberian and Chukchi
Sea, in accordance with an increase in the proportion of marine-derived organic
matter due to Pacific influence towards the East. From 40 to 3000 m water depth
range, carbon mineralization rates decrease only by about a factor 20 from the
shelf to the slope, which is significantly less than the 100- to 1000-fold decrease
observed in other shelf-slope environments. These findings indicate that organic matter
on the Siberian shelf and slope is already significantly degraded and efficiently
buried once it is deposited after land-sea transport in the shelf and slope sediments. |
|
|
|
|
|
|