Initial reports of landslides induced by the Haiti earthquake

It is inevitable that the Haiti earthquake will have triggered landslides, especially in the mountains and in the slum areas built onto the hillsides around the large cities. At present it is not possible to quantify how large these impacts will have been, but some reports are starting to emerge:

The BBC live coverage has this report:
Emmet Murphy, Jacmel, Haiti, emails:I was driving through the mountains when the car started to shake. It was like a very strong wind was blowing and I nearly lost control of the car. Rocks started falling on the road. I continued driving slowly and I saw people in the road screaming. The mountain was collapsing and a building to one side had already fallen down. A huge dust plume raised from the valley floor. I drove further and found the road totally blocked by a massive landslide on the road. I just knew that if I had reached that spot five minutes earlier, I would have been killed. I had to abandon the car and continue on foot.
Meanwhile, this blog from Bermuda is reporting that: "Slum areas have also been badly hit by landslides."

As well as a rather peculiar earthquake prediction, HaitiXchange has this picture of the slums around Port-au-Prince, the capital city, before the earthquake, which graphically illustrates the likely problem in this area:


Meanwhile this extraordinary Youtube video shows the aftermath of the earthquake from a vantage point high above the city. Again, the height of the hills is an indication of the likely landslide problems, but the major point here is the dust pall across the city, thrown up by collapsing buildings:



Finally, as per my earlier post, the lack of news from areas outside Port-au-Prince is a very major worry. I am sure that the picture there is very serious indeed.

On a personal note, I am in New Zealand so cannot be contacted in my office. My mobile number is +44 7983 702717. It will be on for the next few days if you need to contact me.

Haiti - some thoughts on disaster reporting by the media

Watching the reports of the earthquake disaster in Haiti coming in, I thought it might be useful to share some observations on the reporting of the immediate aftermath of disasters in less developed countries:
1. Everything stops at night. At the time of writing it is still night time on Haiti. In the aftermath of an earthquake electricity and power supplies are wiped out, so for the night time period it appears that the disaster is not as bad as is feared. As the sun comes up so the reports on the true picture start to emerge, and the fatality statistics start to increase rapidly. This increase will continue for several days at least, but may ultimately exceed the final toll;
2. The initial focus is often wrong. In the immediate aftermath of a disaster the initial focus of the media reports is often on the biggest city. This is rarely where the biggest impact has occurred, but it is most accessible so will be the focus of the reports.
3. No news is very, very bad news. The biggest impacts are often in rural areas with the highest levels of shaking. These areas had poor communications to start with, but when an earthquake strikes the roads become blocked, power is lost and there is no telephone service. Therefore, no news comes out for some time after the quake. The picture is actually the opposite of the obvious. If news starts to emerge quickly from those areas with the highest shaking then the picture is not as bad as we feared - at least some communications are open - although it may still be quite grim. If there is almost no news at all from the rural areas for a day or two, then the picture is probably very bad indeed, with almost all of the communications wiped out.
4. The media focus will quickly change to the foreign rescue teams. However, although these efforts are valuable, their overall impact is very small. The real work is actually done by local people - most rescues are made by untrained people in the first 24 hours - this should really be the focus.

At the time of writing the reports seem to be focused on Port-au-Prince, with nothing from the areas to the southwest that have been worse affected. This is not a good sign.

The likely impacts of the Haiti earthquake

The earthquake in Haiti is likely to have caused very high levels of damage and many fatalities. The USGS is currently reporting the earthquake as magnitude 7.0 at a shallow depth (only 10 km), which will have led to high ground accelerations for a large area of the country:
The USGS PAGER analysis, which examines the vulnerability of the population is the affected area places three large communities (Petit Goave, population = 15,000; Leogane, 12,000; and Grand Goave, 5,000) in the intensity (MMI) = X area and one community (Gressier, 4,000) in the MMI=IX zone. Very worrying in the city of Carrefour (population = 442,000 people) in the MMI=VIII zone and both Port au Prince (population =1.235 million) and Delmas (population = 383,000 people) in the MMI=VII zone.

A reminder of the levels of damage associated with the higher intensities is as follows:

MMI=VIII. Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse; great in poorly built structures. Panel walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, walls and monuments. Heavy furniture overturned. Sand and mud ejected in small quantities. Changes in well water. Persons driving cars disturbed.

MMI=IX. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb; great in substantial buildings with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken.

MMI=X. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations; ground badly cracked. Rails bent. Landslides considerable from river banks and steep slopes. Shifted sand and mud. Water splashed, slopped over banks.

Needless to say Haiti's building stock is in general not designed to withstand seismic events.

Unfortunately, Haiti has long featured large in the fatal landslide catalogue. The major issue, as I highlighted in this post from September 2008, is that the hillsides have been stripped bare for firewood, and so are very vulnerable to landslides. Thousands have been killed in mudslides, especially around the city of Gonaives, in the last decade. As the Google Earth image below shows, the area affected by the earthquake is mountainous:


It seems likely that landslides will represent a major problem in the rural areas. The news that emerges from Haiti over the next few days is likely to be very grim indeed. The combination of a large earthquake at a shallow depth very close to major population centres in an essentially failed state that is the poorest country in the western hemisphere is likely to have induced a truly fearsome outcome.