[Folda] Fwd:[Jhi] Reminder - Today's Seminar 12:30 - Freysteinn Sigmundsson: Rheology of Iceland

[Siqi Li]

-------- Original Message -------- 
Subject: [Jhi] Reminder - Today's Seminar 12:30 - Freysteinn Sigmundsson: Rheology of Iceland 
Date: Friday, September 8, 2017 08:29 GMT 
From: Maxwell Christopher Brown <maxwell at hi.is> 
To: jhi at hi.is 
 
 
Dear all,

Today's seminar will be given by:

Freysteinn Sigmundsson (Nordic Volcanological Center, Institute of Earth 
Sciences, University of Iceland)

Title: Rheology of Iceland

Abstract: Rheology, the relation between applied stress and resulting 
strain and displacement, influences response to load changes on the 
surface of the Earth but also a variety of geological processes, 
including hot spot – ridge interaction, plate spreading processes, and 
volcano dynamics. Viscosity is the representative parameter on a long 
time scale, and elastic strength parameters on a short time scale. 
Geodynamical studies constraining these will be reviewed, and 
implications of models discussed. The order of magnitude of mantle 
viscosity under Iceland is well constrained to be in the range 1e18-1e19 
Pa s; one or several orders magnitude lower than inferred in global 
models. The short-term response to surface loads in Iceland is 
characterized by mantle Young’s modulus with values 2-3 times lower than 
in global models. Rheology parameters can be expected to vary 
significantly within the crust, with strong local anomalies at central 
volcanoes due to elevated temperature and also abundance of weak rocks 
within calderas. A more advanced approach towards evaluating rheological 
response is to consider laboratory results on rock behavior and 
temperature dependent rheology; an approach that may provide improved 
understanding of volcano deformation.

Is rheology important for understanding dynamics of divergent plate 
boundaries?
http://www.bbc.com/earth/bespoke/story/the-cracks-ripping-earth-apart/index.html

Date: Friday, 8th September
Time: 12:30
Place: 3rd Floor meeting room, Askja

All are welcome.

Best wishes
Maxwell

-- 
Maxwell Brown
Research specialist
Institute of Earth Sciences
University of Iceland
Askja, Room 333
Sturlugata 7
101 Reykjavík
Iceland
  
email:maxwell at hi.is
tel (office): +354-525-4730
tel (lab): +354-525-4794
tel (mobile): +354-832-0015