Bangladesh fits right on the
farthest eastern border of the Indian continental plate, right next to the
plate boundary between the Indian Plate and Australian Plate. That boundary is
a subduction zone (according to the map provided by earthguide link). More
specifically it is a continent-continent subduction zone, the Indo-Australian
subduction zone. The Indian and Australian continents used to be part of
Gondwana which was located further south, where Antarctica is now. Gondwana was
also comprised of New Zealand, modern Antarctica, Tasmania, New Guinea, and New
Caledonia (that one I did not know about). When Gondwana broke apart, all its
pieces began their drift to their current positions. India smashed into the
Asian subcontinent, forming the Himalayan belt approximately 65 mya. The
Australian plate drifted just behind the Indian plate and ended up colliding
with it. One of the more interesting things which I learned in the preliminary
research I did for this assignment was regarding the potential that these two
plates may be breaking apart because the two plates are moving northward at two
different rates. It is actually strangely difficult to find any meaningful
science regarding the tectonic movement in this area because the interwebs are
crammed with blogs such as my own instead of journals. Also Bangladesh is shown on every map at a really
obnoxious angle from which it is hard to ascertain if it is on the boundary of
the Indo-Eurasian plate boundary or the Indo-Australian boundary. I digress. When
Bangladesh experiences earthquakes they will often be sort of massive aftershocks
from the Indian sub-continent continuing northward into the Asian continent. I
have a USGS app on my phone which alerts me of earthquakes around the world.
Sometimes Bangladesh pops up. Usually the quake is no bigger than a 4.0. Many
of these quakes occur on the India-Bangladesh border. I do not think I have
covered everything. As I noted before, there is a lot of information to wade
through and I am trying to narrow it down to good sources. I may add more to
this entry later.
Hu,
Xiumian., et al., Late Cretaceous-Palaeogene Stratigraphic and Basin Evolution in the Zhephere Mountains of
Southern Tibet: implication for the timing of India-Asia Initial collision:
Abstract. Basin Research, 2011. Print.
Najman,
Yani., et al. Timing of India-Asia Collision Geological, Biostratigraphic, and
Palaeomagnetic Constraints. Journal of Geophysical Research, VOL. 115, (2010).
Print.
Also relevant to my citations, if
anyone ever has the time to watch the BBC Earth Series (1998), it is really
good and it is a good visual way to understand how the earth came to look the
way it does now, geologically speaking.
I particularly enjoy episode 5, Roof of The World, although some of the specific
information is a little outdated, it is a good documentary if you like geology.
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