Updated with new satellite imagery, Saturday 26 February, 11am.
New Zealand is currently experiencing one of its worst natural disasters since the Hawke's Bay earthquake in 1931. One factor that differs significantly between now and then, is the availability of satellites and space applications. While New Zealand has no satellites of its own, through international disaster charters, the first satellite images have been obtained, highlighting areas of damage.
The following images relate to the 6.3 magnitude Earthquake in the Christchurch region, centred near Lyttelton.
First information products
Click the images for full-size view (Files are approximately 6MB).
Disaster Extent Map - Flooding and Silt
Christchurch Centre, Acquired 23 February 2011. Annotated with known locations of damaged buildings.
Produced 25 February, 9pm.
This image/map shows areas of seismic induced flood traces (liquifaction traces) - highlighted in red, as observed in the satellite images.
Damage Assessment Map - Detail
Christchurch Centre, Acquired 23 February 2011. Annotated with known locations of damaged buildings.
Updated with more information overlays (25 February, 18:50)
This image/map shows locations of damaged buildings and other key locations around Christchurch.
View earlier damage assessment maps:
These satellite images were provided by the French space agency (CNES) under the UN Disaster Charter, at the request of the NZ Ministry of Civil Defence and Emergency Management.
A similar charter activation has been actioned via the Asia-Pacific Regional Space Agency's (APRSAF) Sentinel Asia disaster monitoring scheme.
Satellites and disaster management
The initial images show the strengths and weaknesses of the various satellite imagery: On one hand, satellite images give a birds-eye view of the landscape, providing a complete picture of the location. Comparison of pre- and post-disaster images can allow quick identification of affected areas. However these initial satellite images are essentially photographs, and so are obscured by dust, smoke, and cloud cover. Radar-based satellite sensors will be able to provide views through this cover, but these images are not available yet.
Several international or regional efforts exist to provide free satellite data in response to natural disasters (flooding, earthquakes, etc) and man-made disasters (oil spills, etc). To KiwiSpace' knowledge, New Zealand is not a formal member of these charters, but have been able to access them through through partner agencies and international goodwill. The disaster organisations not only provide the raw images, but also processing of the data – to help deliver meaningful information products, especially to nations who may not have this domestic capability.