Phil R Cummins | Nature Vol 449 | 6 September 2007 | 75
My name: Johnathan Lau
My tutor’s name: Dr P Sushko
The potential for giant tsunamigenic earthquakes in the northern
Bay of Bengal
Presenter: The issue we are going to discuss today is tsunami. Before we get to the
interesting part, I would like to welcome our guest, Johnathan Lau, a physics
undergraduate from UCL that is interested in this topic.
John: Hello! Thank you for inviting me to the show. Before we start, let’s get familiar
with the terms. Our topic today is “tsunami”, so what’s tsunami? I guess most people
at least heard this term after the dramatic tsunami occurred on Boxing Day 2004. A
tsunami is a series of waves created when a body of water, such as an ocean, is
rapidly displaced. This is mainly caused by earthquakes and volcanic eruptions above
or below water. Some people might also heard of the term “tsunamigenic earthquake”
but not sure what exactly it is. I got a nice definition from google; it says “any
earthquake which produces a measurable tsunami. An earthquake that produces an
unusually large tsunami relative to the earthquake magnitude.”
Presenter: Can you tell us a bit about the tsunami in 2004?
John: The tsunami on Boxing Day 2004 was caused by an undersea earthquake, with
an epicentre off the west coast of Sumatra, Indonesia. Most of landmasses bordering
the Indian Ocean were affected; water waves were striking as high as 30 meters,
killing more than 225,000 people.
Presenter: Could a tsunami happen again in around the same area?
John: Most scientists are aware that there are potential threats of another giant
earthquake in high off central Sumatra. However, recently Phil R Cummins wrote a
letter to the “Nature” – one of the popular science magazine and suggesting that there
is also risk for giant tsunamigenic earthquakes in the northern Bay of Bengal.
Presenter: Why Phil R Cummins suggested there is also risk of tsunami in the
northern Bay of Bengal?
John: A (computer) simulation was carried out. An earthquake with magnitude 8.8
position along the Arakan (The former name of Rakhine State in Myanmar) coast.
Result shows that this earthquake would generate a large tsunami which affects the
northern tip of the Bay of Bengal.
Presenter: In the simulation why is the earthquake placed along the Arakan coast?
John: From studies, it shows that there was an earthquake near that area in 1762 and
taking into consideration of plate and other geological movements. They think that’s
the place where earthquake most likely going to occur.
Presenter: Should people be worry about this?
John: In this simulation, the magnitude of the earthquake is taken as 8.8; this is the
worst scenario of the 1762 event. Also, it may be over 200 years before a similar
event occurs. However, the next tsunamigenic earthquake in the Arakan subduction
zone may occur much sooner but not be this large. We should also keep in mind that
along the coastal region has an extremely high population density. Therefore, Phil R
Cummins suggested that the risk of a major tsunami in the northern Bay of Bengal
should be taken seriously.
Presenter: Once again, thank you for our guest Johnathan Lau, hope this short radio
show is entertaining and educational. Thank you for listening.