Puzzles and Challenges
Can you solve the photo interpretation challenge?
This data covers a collection period of 20 years, displayed on a yellow-to-red scale.

Figured it out? Check your answer
It's seismic activity.
Concentrations of seismic activity can be seen along the Alpide Belt, the second-largest earthquake belt in the world. This belt extends from the Indonesia islands of Java and Sumatra in South-East Asia to the Himalayan region of the Indian sub-continent through Central Asia into the Mediterranean Sea, and out into the Atlantic Ocean.