While everyone’s attention is drawn to Antarctic ice sheet, ESA’s CryoSat satellite reveals melting ice in Greenland has recently contributed twice as much to sea-level rise as the prior two decades (original link).
Between 2011 and 2014, Greenland lost 1 trillion tonnes of ice which corresponds to 0.75 mm contribution to global sea-level rise each year, twice the average of the preceding two decades (summary video).
The Richat Structure, known as the Eye of the Sahara or of the Africa, is located in west-central Mauritania. 50km diameter circular feature consists of a series of 100 meter high mountains made of Cambrian rocks.
It is hypothetically thought that erosion carved away soft sediments and dome-shaped bulge movement created circular feature, but the probable mechanism is still under discussion.
See earthview photo gallery with web-globe: LiVEARTH