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| Titel |
Geomorphological analysis of the drainage system on the active convergent system in Azerbaijan, NW Iran |
| VerfasserIn |
Amaneh Kaveh Firouz, Jean-Pierre Burg, Emanuele Giachetta |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250134631
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| Publikation (Nr.) |
 EGU/EGU2016-15375.pdf |
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| Zusammenfassung |
| Rivers are important landforms to reconstruct recent tectonic history because they are
sensitive to surface movements, especially uplift and tilting. The most important drainage
basins of NW Iran are, from north to south, the Arax River, the Urmia Lake and the Ghezel
Ozan River catchment. The morphology of the two adjacent catchments draining into the
Caspian Sea, the Arax and Ghezel Ozan were studied to better understand the active tectonics
and the effect of fault activity on morphology and erosion rate of NW Iran. We performed a
quantitative analysis of channel steepness and concavity, from slope-area plots calculated
from digital elevation model. This information has been combined with GPS velocity vectors
and seismicity.
Both catchments developed under uniform climate conditions.
Results show that the two rivers are in morphological disequilibrium; they exhibit profiles
with prominent convexities and knickpoints. The Arax River shows higher channel steepness
and concavity index in downstream part of the profile. Distribution of knickpoints show
scattered elevation between 700m and 3000m. GPS rates display shortening 10
± 2 mma−1 and 14 ± 2 mma−1 in upstream and downstream, respectively. The
river profiles of Ghezel Ozan River and its tributaries reveal more disequilibrium
downstream where channel steepness and concavity index are higher than upstream. Most
knickpoints occur between 1000m and 2000m. The amount of shortening by GPS
measurement changes from upstream 13 ± 2 mma−1to downstream 14 ± 2 mma−1.
Recorded earthquakes, such as Rudbar earthquake (Mw=7.3, 1990), are more frequent
downstream.
The Urmia Lake is surrounded by many small and large catchments. Only major
catchments were considered for the analysis. One of the most active faults, the north Tabriz
fault, corresponds to a major knickpoints on the Talkhe rud River.
Concordance between river profile analysis, GPS and seismotectonic records
suggests that the characteristics of the river profiles are related to active fault systems. |
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