It has been a while since I have made some scientific comments about an earthquake so for those of you who are not aware, I am an earthquake geologist and part of my day job is research and public outreach related to earthquakes.
Needless to say the earthquake over the weekend in Nepal got my attention and my response may be a bit surprising – no surprises here.
If you have been following the coverage you know that the most commonly reported magnitude measurement puts it at 7.8 although another slightly different magnitude measurement scale gives is a value of 8.1. For the record those of us in the business don’t spend a lot of time fretting the differences between the scales. Let’s just say that they all measure the event in slightly different ways and each has it’s advantages and disadvantages. The bottom line is that it is a big earthquake.
The most interesting scientific result to me is the finite fault model. This is a method of reconstructing the behavior of the earthquake as the fault breaks and it is interesting to note that the fault started breaking on the west end and broke to the east. In addition, the larger fault offsets were in the eastern portion and both of these circumstances would have increased the damage in the Kathmandu area. In addition, at 15 km deep it was relatively shallow and therefore more destructive. In addition, Kathmandu sits in a basin with soft sediments which would also amplify the shaking for a couple of different reasons. The circumstances of this quake were not in its favor.
You may have caught in the news coverage that there was a slightly larger earthquake in this area back in 1934 so these events do occur on a regular basis. There have been some other smaller earthquakes in the area but this event does overlap with both the 1934 event and the previous substantial event back in A.D. 1255. The Earth Observatory of Singapore has a nice page with a lot of technical information about the event. There is also a set of slides from IRIS (available in a PDF file) that gives a great overview of the event.
The bottom line is that this is a plate boundary where India is colliding with and going under Asia — very large earthquakes are to be expected. The Himalaya are being pushed up and Southeast Asia is getting squeezed out the side. In fact, this event moved Kathmandu about 10 feet south and raised the central Himalaya a little bit and Mt. Everest is most likely a bit taller, but think in terms of an inch, not feet. The majority of the motion is horizontal and this was a pulse in the constant shortening of Asia that is bringing Beijing closer to New Delhi. [Update: My initial uplift calculations were a bit off and Mt. Everest appears to be on the far side of the flexture line and is actually now an inch shorter.]
Aftershocks will continue for a while but with a couple in the magnitude 6 range and a good number of magnitude 5 events everything is looking typical. The big question is triggering and whether the stress redistribution of this event will make another large earthquake more – or less – likely. It would seem that triggering another earthquake is likely but it is best to think on the scale of decades to centuries and not a few days, months or years.
So what Presbyterian news has come out related to this?
First, branches are reporting on the status of their workers in that area: The missionaries from the neighboring Mizoram Synod are reported safe and have declined evacuation and will continue working there. Similarly, the Presbyterian Church in Ireland and the Church of Scotland have reported that their workers are safe and furthermore that all the workers with their partner agency, the United Mission to Nepal, are safe. And the Moderator of the Free Presbyterian Church of Northern Ireland returned from Nepal the day of the earthquake and the church reports that members and workers with the Free Presbyterian Church of Nepal are shaken but safe.
Second, work has kicked into high gear across the Presbyterian family to solicit relief aid for the country. A quick rundown:
- Church of Scotland is working with Christian Aid and has repurposed a fundraiser this weekend for Nepal earthquake aid
- Cumberland Presbyterian Church has issued an appeal through its Ministry Council
- Presbyterian Church (U.S.A.) has an appeal through the Presbyterian Disaster Assistance which is working with the ACT Alliance
- Presbyterian Church in America is working through its Mission to the World agency
- Presbyterian Church in Canada is responding through the Presbyterian World Service & Development (PWS&D)
- Presbyterian Church in Ireland has provided an initial £60,000 and has launched an appeal and is working with its Mission Overseas agency
- Presbyterian Church of Aotearoa New Zealand has highlighted a pastoral letter from the Christian Conference of Asia and is partnering with Christian World Service in the relief efforts [update added 30 April]
- Free Church of Scotland has put out an appeal and is taking donations through their payment site. [update added 30 April]
- Evangelical Presbyterian Church is recommending two agencies for donations and will accept donations to be passed on to one of them, World Relief. [update added 1 May]
- ECO: A Covenant Order of Evangelical Presbyterians is partnering with World Renew. [update added 1 May]
- Presbyterian Church of Taiwan issued Condolences and Support. [update added 1 May]
I will keep updating that list as I hear of more branches who are reaching out with aid for that country.
As we look ahead prayers for the country are certainly in order. The death toll has passed 5,000 and based on the building styles and the disruption of communication with smaller villages I think the Prime Minister’s estimate of 10,000 dead is unfortunately a real possibility. Thank you for your prayers and however you can help out in this disaster.