[Folda] Fwd: [Jhi] MS lecture in glacial geology tomorrow, Thursday 26th of January

[Deirdre Clark]

Daniel Ben-Yehoshua's will present his MSc thesis tomorrow at 15:00, please
note the location change to Árnagarður, lecture hall 201!

---------- Forwarded message ----------
From: Ólafur Ingólfsson <oi at hi.is>
Date: Wed, Jan 25, 2017 at 12:15 PM
Subject: [Jhi] MS lecture in glacial geology tomorrow, Thursday 26th of
January
To: Jhi at hi.is


*You are all invited* to attend a MSc presentation in glacial geology: *Daniel
Ben-Yehoshua* will present his MSc thesis on *Crevasse-Squeeze ridges in
Trygghamna, Svalbard*.

*Date and time*: Thursday 26th of January, at 15:00

*Place*: Árnagarður, lecture hall 201

I hope you will find time to attend, as Daniel´s project deals with some
outstanding research questions regarding the formation of certain glacial
landforms that occur in front of surging glaciers in the Arctic. His
lecture will also give you a good sense of what it is like to do glacial
geological fieldwork in the Arctic, as well as giving insight into the
combination of methods used for descriping, documenting and interpreting
glacial landforms.

*Abstract*:

Glacial geologists have been discussing the processes behind the formation
of Crevasse-Squeeze Ridges (CSRs) since they were first described from the
forefield of Eyjabakkajökull, Iceland, in the mid 1980s. To date, CSRs are,
together with concertina eskers, the only landforms that have been
described exclusively in the forefields of surge-type glaciers. However,
much remains to be learned about these ridges and their glaciological
significance. This thesis describes geometrical and transverse sediment
ridges appearing after surge events of polythermal glaciers in
Trygghamna, West Svalbard. In order to understand the geomorphic context of
these landforms, detailed maps were produced via remote sensing and field
mapping. These maps illustrate striking differences in CSR configurations
found in marine and terrestrial settings. Historical images from 1936 were
used to compare the geometry of former glacier surface structures with
mapped CSRs. Furthermore, analysis of CSRs in cross-sections sheds light on
the architecture and sedimentology of these formations. Results from
Trygghamna suggest that basal till was squeezed into basal crevasses during
a surge and transported englacially before deposition. Mapped landform
assemblages suggest that at least two glaciers in Trygghamna have surged in
the past. Additionally, CSRs are observed in an area of a former glacial
shear-zone between a surge-type and a non-surge-type glacier. A conceptual
model for the formation and preservation of CSRs in Trygghamna is proposed.
The results of this thesis not only further contemporary understanding of
CSRs in Trygghamna, but may also apply to large-scale glacial or ice stream
settings.



Ólafur Ingólfsson

Professor, geology



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-- 
Deirdre Clark, PhD Research Fellow
University of Iceland | Háskóli Íslands
Institute of Earth Sciences
Sturlugata 7, Askja, Room 235
101 Reykjavík, Iceland

+354 525 4275 (Office)
+354 690 5745 (Mobile)
dec2 at hi.is
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