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| Titel |
Impact of the 2008 Wenchuan earthquake on river organic carbon provenance:
Insight from biomarkers |
| VerfasserIn |
Jin Wang, Xiaojuan Feng, Robert Hilton, Zhangdong Jin, Tian Ma, Fei Zhang, Gen Li, Alexander Densmore, A. Joshua West |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144681
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| Publikation (Nr.) |
 EGU/EGU2017-8538.pdf |
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| Zusammenfassung |
| Large earthquakes can trigger widespread landslides in active mountain belts, which can
mobilize biospheric organic carbon (OC) from the soil and vegetation. Rivers can
erode and export biospheric particulate organic carbon (POC), which is an export
of ecosystem productivity and may result in a CO2 sink if buried in sedimentary
deposits. Our previous work showed that the 2008 Mw 7.9 Wenchuan earthquake
increased the discharge of biospheric OC by rivers, due to the increased supply by
earthquake triggered landslides (Wang et al., 2016). However, while the OC derived from
sedimentary rocks could be accounted for, the source of biospheric OC in rivers
before and after the earthquake remains poorly constrained. Here we use suspended
sediment samples collected from the Zagunao River before and after the Wenchuan
earthquake and measured the specific compounds of OC, including fatty acids, lignin
phenols and glycerol dialkyl glycerol tetraether (GDGT) lipids. In combination
with the analysis of bulk elemental concentration (C and N) and carbon isotopic
ratio, the new data shows differential export patterns for OC components derived
from varied terrestrial sources. A high frequency sampling enabled us to explore
how the biospheric OC source changes following the earthquake, helping to better
understand the link between active tectonics and the carbon cycle. Our results are also
important in revealing how sedimentary biomarker records may record past earthquakes. |
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