Earthquakes, floods, sea-level rise and sudden shifts in river courses threaten many of the 150 million Bangladeshis living in the low-lying Brahmaputra River delta. Scientists from Lamont-Doherty, Dhaka University and other institutions have begun a five-year project to understand the hazards and the possible hidden links among them. Lamont geophysicist Michael Steckler keeps us up to date on the work.
Geohazards in Bangladesh
Fellowship of the Seismometers
I am back in Bangladesh to start deploying equipment for a large new project. Results from our last project showed there is a large earthquake hazard here. We demonstrated that the Sumatra subduction zone, where India plunges beneath Asia, continues to the north under Bangladesh. The subduction down at Sumatra caused the 2004 earthquake and tsunami that killed over 230,000 people. Even though the plate boundary comes onshore, which is unusual for subduction zones, is it still active with the world’s largest pile of sediments, the Ganges-Brahmaputra Delta, entering it. We have designed an experiment to investigate this plate boundary across three countries: Bangladesh, India and Myanmar.
Our first step is to install 29 seismometers and 6 GPS receivers in Bangladesh. To do this, we have a team of 11 people. Most of us will be here for three and a half weeks. There are five of us from Lamont, two engineers from PASSCAL and UNAVCO, organizations that provide support and equipment to NSF projects like ours, and four from Dhaka University. Ahead of us, we shipped over two tons of seismic equipment and carried over 300 pounds with us on the plane. Thanks to a two-hour delay due to fog in Dhaka, our flights lasted a full 24 hours, and longer for the two engineers coming from Colorado and New Mexico. We then spent the next several hours at the airport getting all our luggage, getting them through the huge backup at customs from all the delayed flights, changing money, and getting local phone numbers.
At a lunch stop, four members of our team who have never been here before tasted their first Bangla food. So far, they are all enjoying it. We then arrived at the Dhaka University of Engineering and Technology (DUET), north of that city to set up our base.
When we arrived we found out that the seismic equipment is being help up by customs. Since the packing list mentions the GPS antenna that gets exact time for the seismometers, customs referred it to the Telecommunications Regulatory Commission. Humayun went back to Dhaka and spent the day there dealing with it, while Alissa and I tried to find the documents he needed to show the antennae only receive signals and do not cause not interference.The paperwork is slowly going through the bureaucracy and we hope it will be released tomorrow.
Meanwhile, we spent the time running around Joydebpur shopping for the materials we need. The seismologists need to build underground vaults to hold the instruments, while the GPS team needed grounding rods and wire. Most of seismic supplies were bought or ordered, so they should be ready to move out ahead of schedule even with the delay, if they get it tomorrow. The GPS team finished our shopping so tomorrow we will pack up, hopefully be able to fit everything in one van, and take off. It will be Keith from UNAVCO, Sanju from Dhaka University and myself.
When they are done shopping and testing, the seismic team will split into two 4-person groups for the installations, starting with the dense central line of stations. We will hopefully see one of them by the end of the week when they arrive in the Srimongol area, where we are going. The other team will initially work from here at DUET. These are the two ends of the dense lines in Bangladesh and they will spend the following week deploying towards each other.
Of course we had too much stuff for the van, so the truck will come with us to carry our equipment and then return to DUET. We had the mandatory meet and greet with the president of DUET. In the end, our leaving first thing in the morning stretched to 12:30. We had hoped to stop at one of the sites on the way, but instead we went straight to the Lemon Garden Resort in the hills near Srimongal. The hills in Sylhet in the northeast part of Bangladesh are covered in tea estates. There are a growing number of resorts in the hills as well. Lemon Gardens has beautiful grounds, and tomorrow we will see if there is a good spot for a GPS.