Thread: IRIS WEBINAR: Tomographic Study of Lithosphere Dynamics in the Eastern Mediterranean - 3/12, 2 PM Eastern

Started: 2014-03-06 00:52:08
Last activity: 2014-03-11 20:05:27
Topics: Early Careers
"A Snapshot of Eastern Mediterranean Lithosphere and Upper Mantle: Clues
for the Demise of Tethys Ocean" will be presented at 2 pm EST (6 pm UTC)
on Wednesday, 3/12.

Please register *only* if you intend to watch the webinar live:
https://www2.gotomeeting.com/register/857750082

You will be emailed a confirmation containing a link for watching the
live broadcast. A recording will be subsequently posted here:
http://www.youtube.com/user/IRISEnO. Access to older webinars, along
with related materials and information is found here:
http://www.iris.edu/hq/webinar/

Presenter: Dr. C. Berk Biryol, Postdoctoral Research Associate,
University of North Carolina at Chapel Hill

Abstract: The tectonics of the Mediterranean region is characterized by
an intricate configuration of arcuate subduction zones and mountain
belts. The evolution and the geodynamics of these zones are controlled
by closure of Tethys Ocean between converging Eurasia and Africa. The
interplay between convergence-related compression and slab rollback
related extension is further complicated by processes such as
termination of subduction, tearing and detachment of subducting oceanic
lithosphere. Our recent studies using various seismological techniques
reveal the complexity of lithospheric and upper mantle structures in the
Anatolian region using a dataset composed of over 200 seismic stations.

Our body-wave tomography results reveal segmented layout of the Aegean
and the Cyprus slabs that are separated from each other by a tear as
wide as 300 km beneath Western Anatolia. The geometry of this tear
suggests it was formed by differential subduction and rollback rates
along the Aegean and Cyprus trenches. This configuration of slabs and
the associated geodynamic setting is consistent with our upper mantle
seismic anisotropy observations from shear-wave splitting measurements
favoring a SW direction of asthenospheric flow. We infer that this flow
is controlled by the differential forces acting on the upper-mantle,
exerted by the slab-roll-back taking place along the Aegean and the
Cyprean Subduction Zones. The gaps associated with the slab tears and
edges are occupied by slow velocity material and underlie major volcanic
provinces of Anatolia. Recent ambient noise tomography results reveal
the fragmented nature of the Anatolian lithosphere with seismic velocity
variations across paleo-suture zones and major active-tectonic features
such as the North Anatolian Fault Zone.

Overall, our observations hold important clues about the effects of
Tethys Ocean closure on the structure of subduction zones and
lithosphere in the eastern Mediterranean.

Please direct any related questions or the name of your favorite seismic
station to Andy Frassetto (andyf<at>iris.edu).

System Requirements
PC-based attendees: Windows® 8, 7, Vista, XP or 2003 Server
Mac®-based attendees: Mac OS® X 10.6 or newer
Mobile attendees: iPhone®, iPad®, Android™ phone or Android tablet


  • REMINDER: "A Snapshot of Eastern Mediterranean Lithosphere and Upper
    Mantle: Clues for the Demise of Tethys Ocean" will be presented at 2 pm
    EDT (6 pm UTC) on Wednesday, 3/12.

    Please register *only* if you intend to watch the webinar live:
    https://www2.gotomeeting.com/register/857750082

    You will be emailed a confirmation containing a link for watching the
    live broadcast. A recording will be subsequently posted here:
    http://www.youtube.com/user/IRISEnO. Access to older webinars, along
    with related materials and information is found here:
    http://www.iris.edu/hq/webinar/

    Presenter: Dr. C. Berk Biryol, Postdoctoral Research Associate,
    University of North Carolina at Chapel Hill

    Abstract: The tectonics of the Mediterranean region is characterized by
    an intricate configuration of arcuate subduction zones and mountain
    belts. The evolution and the geodynamics of these zones are controlled
    by closure of Tethys Ocean between converging Eurasia and Africa. The
    interplay between convergence-related compression and slab rollback
    related extension is further complicated by processes such as
    termination of subduction, tearing and detachment of subducting oceanic
    lithosphere. Our recent studies using various seismological techniques
    reveal the complexity of lithospheric and upper mantle structures in the
    Anatolian region using a dataset composed of over 200 seismic stations.

    Our body-wave tomography results reveal segmented layout of the Aegean
    and the Cyprus slabs that are separated from each other by a tear as
    wide as 300 km beneath Western Anatolia. The geometry of this tear
    suggests it was formed by differential subduction and rollback rates
    along the Aegean and Cyprus trenches. This configuration of slabs and
    the associated geodynamic setting is consistent with our upper mantle
    seismic anisotropy observations from shear-wave splitting measurements
    favoring a SW direction of asthenospheric flow. We infer that this flow
    is controlled by the differential forces acting on the upper-mantle,
    exerted by the slab-roll-back taking place along the Aegean and the
    Cyprean Subduction Zones. The gaps associated with the slab tears and
    edges are occupied by slow velocity material and underlie major volcanic
    provinces of Anatolia. Recent ambient noise tomography results reveal
    the fragmented nature of the Anatolian lithosphere with seismic velocity
    variations across paleo-suture zones and major active-tectonic features
    such as the North Anatolian Fault Zone.

    Overall, our observations hold important clues about the effects of
    Tethys Ocean closure on the structure of subduction zones and
    lithosphere in the eastern Mediterranean.

    Please direct any related questions or the name of your favorite seismic
    station to Andy Frassetto (andyf<at>iris.edu).

    System Requirements
    PC-based attendees: Windows® 8, 7, Vista, XP or 2003 Server
    Mac®-based attendees: Mac OS® X 10.6 or newer
    Mobile attendees: iPhone®, iPad®, Android™ phone or Android tablet

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