Watching ice shelves break up with Sentinel-1

The animation below shows the evolution of Thwaites glacier eastern ice shelf in West Antarctica, from July 2016 to May 2017. I made it with 45 quicklooks of Sentinel-1 radar images processed by the Alaska Satellite Facility and available via the vertex data portal. All images were acquired in interferometric wide swath mode (polarization HH, only ascending passes, path: 65, frame: 914) and projected to ground range.

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Erratum to "Landslides in Kyrgyzstan captured by Sentinel-2"

In this post "Landslides in Kyrgyzstan captured by Sentinel-2" I showed two landslides that I identified as the Kurbu and Ayu landslides, both featured in the AGU landslide blog. However, as pointed out by Isakbek Torgoev, the Kurbu-Tash landslide is located about 5 km farther south than the one I found on the Sentinel-2 image of Apr 29. The actual Kurbu-Tash was not visible in this image due to cloud cover, but today I found a more recent image (May 19), where the Kurbu-Tash landslide is evident.. and it's even more massive! From this image I estimate that the runout distance of the Kurbu-Tash is about 7 km and not 3.5 km.
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Sentinel-2 adds colors to the 2017 super bloom in California

Texas had the super bowl in 2017 but California got the super bloom!


After its worst drought in 1,200 years, California is now experiencing one its wettest year. The Sierra Nevada snowpack is currently one of the biggest ever recorded. In February, severe winter rainfalls caused the evacuation of many California residents under the threat of the Oroville Dam failure.


Now, this unusual level of rainfall triggered the blossoming of flowers that were in a dormant state. The Washington Post collected some photographs and noted that it was so so massive that you can see it from space (images were provided by Planet, a California-based remote sensing company).


How does it look like in Sentinel-2 imagery? Below is the comparison between two Sentinel-2 images acquired in spring 2016 vs. spring 2017 near the Carrizo Plain National Monument (see by yourself in the sentinel-playground).


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Last Sunday's snow cover map from Sentinel-2

We know that fast distribution of satellite products is critical for many applications, including the planning of your next weekend.


Olivier just announced that Theia is now delivering Sentinel-2 Level 2A data in near real time. This is great because today I was able to make the snow cover map of the Pyrenees on Sunday at 20-m resolution.


The L2A image was actually published on Tuesday afternoon so I could have posted this snow map two days ago.

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Un nouvel algorithme de détection des nuages pour la Bretagne

Ce nouvel algorithme baptisé MACCROW (Multitemporal Atmospheric Correction and Cloud Retrieval Of Western-France) a été développé par l'équipe MACCS pour résoudre le cas spécifique des régions à forte nébulosité. Comme nous l'a expliqué Olivier Hagolle, chercheur au Cesbio, "l'algorithme se base sur le fait que la reflectance au sommet de l'atmosphère chute brutalement lorsque le ciel s'éclaircit. Ces évènements aberrants peuvent être détectés par un test de Fisher puisque leur distribution statistique suit généralement une loi de Poisson. Les premières validations ont donné des résultats satisfaisants (kappa=0.76). Il reste que certaines trouées passent encore à travers les mailles du filet."

La série de Plouguemeau traitée par MACCROW. Les zones claires sont délimitées en rouge.

NB) l'image du 07-aout-2016 a été volontairement exclue car elle était trop claire et donc faisait planter l'algorithme.