Natural catastrophies remind humans that they are still only second to nature on this planet. Sometimes we are not even second: When forces break open and move the ground, like it happened on the 11th of March at 5:46 (UTC) at the coast of Japan along the pacific ring of fire, it can only be compared to a giant kicking an antshive. For us, the ants, there is no real warning, nowhere to run to and hardly any shelter.

A. Soucek (r.) with current satellite photos of Japan at the ESA centre for Earth Observation.

However, when the big clean up starts, we can rely on help from space. Satellites offer a clear view on the area of the catastrophe. With only a few observations complex images can be produced. Fast availability, always being up to date and completeness of data play an important role.

First calculations show which satellites orbit the area at what time. They can not simply be turned around and steered to a different position – they have to follow the laws of physics of their fixed orbits. Thankfully there are plenty of Earth observing satellites nowadays, so that first data are available very fast. However, also too much of good is too much: a worldwide cooperation is necessary. This is ensured by a paper – the “International Charter for Space and Major Disasters”, which was agreed on by the third UNO Space Conference in Vienna 1999 (UNISPACE III). This paper provides a mechanism between different space agensies, enabling them to act effectively in a worst case.

How does this happen? When the catastrophe has happened, the charter is activated by an authorised user – which in the case of Japan is the Japanese Space Agency JAXA. This activation is done like in a movie: With a call at the red telephone which is answered by an “on duty operator”, a role filled by rotation by different member agencies.
The operator passes the call on to the “emergency on-call officer”, who – based on first informations – makes a first plan how and which satellites and mission control centres will be activated. The different Space-Agencies now have to reschedule the flight plans. Who has prebooked observation times might have to wait at this stage.

An important role is taken over by different Service Agencies or Institutes which produce maps and charts out from all the data. Rescue operations rely on this service for their work.

DLR Satellite image Sendai area Japan

What is provided by satellites? Maps show flooded or potentially endangered areas, destroyed infrastructure can be made visible – which is an important tool when rescue teams have to travel into the area or when communication has been cut off. Which bridges are still standing, which train lines are damaged, and where? Satellite images can show the whole scope of a catastrophe by comparing before and after images. A multitude of information can therefore be delievered from space.

24 hours after the first earth quake, high resolution maps showing the scope of destruction were available. In the future, when the worst is over, Insurance companies, City planners and infrastructure agencies will use these maps as well: Who was affected, when and where? How can we learn from this for future plannings?

Satellites are not only essential tools for science. Especially during times of natural catastrophes, they deliver important information. From a safe distance of a couple of hundreds of kilometers, they are the first to provide a complete picture of the situation.

Dieser Artikel ist auch verfügbar auf: German