nepal earthquake

NASA damage maps

February 3, 2016

We recently came across this interesting story about damage maps that NASA created after the Nepal earthquakes last year. We dug a little deeper and found this story on the NASA website, which includes a link to the damage maps viewable in Google Earth.

Grab the KML here. Be sure to also check out the layer labelled “NGA_All_Damage_Nepal_April_30th_2015_points“, which is not turned on by default. It shows the location of damage that has been confirmed. It appears to cover a slightly different area than the damage map and we did identify damage in the imagery on the right hand side of the damage map not covered by this layer.

The damage map is clearly not completely accurate, as it does not have a one to one correspondence with the actually identified damage. According to the NASA article it is based on change between satellite radar images between November 24, 2014 and April 29, 2015. As a result, a lot of changes not related to damage have been picked up. At the top left of the damage map a river really stands out. This is because river beds tend to change significantly over time.

The NASA damage map based on changes between radar images.

The map of directly identified damage overlaid on the NASA damage map.

New Nepal Imagery following May 12th Aftershock

May 22, 2015

Last week we talked about the new imagery in Google Earth following the April 25th Nepal earthquake.

On May 12th Nepal experienced a major aftershock consisting of a magnitude 7.3 earthquake. Just one week later Google Earth already has imagery of Kathmandu and surrounding areas captured on May 14th, 2015.

Left: December 18th, 2014. Right: May 14th, 2015.

Above: A hillside in Sindhupalchowk, north-west of Kathmandu. According to Wikipedia, between the two quakes, 95% of this area’s houses were destroyed.

Left: November 2nd, 2014, Right: May 14th, 2015

Above: The Dharahara tower. Its collapse reportedly killed at least 180 people.

The new May 14th imagery has replaced imagery from May 3rd. Several locations which showed piles of debris from collapsed buildings appear to have been cleaned up since then. We cannot do comparisons as the May 3rd imagery has not yet been put into ‘historical imagery’.

For the locations in this post as well as some other locations we have identified around Kathmandu based on this BBC article download this KML file. For best results, check again in a few weeks when the May 3rd imagery makes it into ‘historical imagery’.

Post-earthquake Imagery of Nepal in Google Earth

May 14, 2015

[Update: Thank you to GEB reader AC for pointing out that the Kathmandu imagery is actually May 3rd imagery (I read the dates wrong) and does show earthquake damage.]

We have been keeping an eye on Nepal in Google Earth to see if any post-earthquake imagery gets added. We found quite a lot of March imagery that was captured before the Earthquake, but added to Google Earth in the last couple of weeks. There is also a fairly large image captured on May 5th, 2015 just over a week after the earthquake.

We also found two small areas with imagery from April 27th, 2015 captured just a couple of days after the earthquake. Interestingly though, they are false colour images and all the trees look red. Most likely a satellite designed to take images only in infra-red that was available at the time, captured imagery of the location and Google has decided the imagery is useful enough to include.

The latest imagery has not yet been added to ‘historical imagery’ so we can’t check the extent of the full image. It is likely a much larger image than what we can see and was probably intended by Google to be visible only in ‘historical imagery’.

Interesting false colour imagery in Nepal captured just days after the earthquake.

To find the above patches of red imagery, and see the approximate extent of the May 5th image, download this KML file.

We have not been able to identify any earthquake damage in any of the imagery. If you spot anything of interest, please let us know in the comments.

Surface deformation from the Nepal Quake

May 7, 2015

We recently came across this article about a map from NASA that shows the deformation caused by the recent earthquake that struck Nepal.

The above map can be downloaded and viewed in Google Earth using this KMZ file.

The movement being measured is the overall vertical movement of the ground as a result of the earthquake. If I read the map correctly, the ground moved upwards with maximum movement at a point just North of Kathmandu. In the above screenshot we have turned on the ‘Earthquakes’ layer (found in the Gallery layer) in Google Earth which shows that the centre of the initial magnitude 7.8 earthquake was further to the North West (the largest Earthquake icon).

DigitalGlobe captured satellite imagery of the region soon after the earthquake and has made it available for free to emergency responders under a Public License for Humanitarian purposes.

It is possible to see the imagery on DigitalGlobe’s website and you can help with the crowdsourcing campaign on the Tomnod website.

We have not yet found a way to download the imagery for viewing in Google Earth.