Sentinel-2 captures the coastal ground uplift after Kaikoura earthquake in New Zealand

On Monday Nov 14 New Zealand was hit by an earthquake of magnitude 7.8. The epicenter was located near Kaikoura on the east coast of the South Island.

 

Yesterday, the NZ Herald published aerial photographs showing tectonic uplift of the seabed of between 2 and 2.5 metres north of Kaikoura [1]. These photos were taken by @TonkinTaylor who posted them on Twitter.

 

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3D views of Aru Co avalanches from Pléiades stereo imagery

A Pléiades stereo pair has been acquired on 2016-Oct-01 just a few days after the second glacier collapse in the Aru mountains. The panchromatic band has 0.5 m resolution, which allowed us to generate a post-event digital elevation model of the area. From this digital elevation model and the Pléiades 2 m multispectral imagery, Etienne Berthier generated these stunning 3D views of the aftermath...

Preliminary estimates of the volume detached from the glaciers are 66 Mm3 (first, north one) 83 Mm3 (second, southern one).

Patagonian skies are not cloudy anymore

"The most usual weather in these latitudes is a fresh wind between north west and south west with a cloudy overcast sky" - Phillip Parker King, Sailing Directions for the Coasts of Eastern and Western Patagonia (1832).

 

Patagonia is a beautiful place to visit but campers know that the weather is extremely variable and the sky is often cloudy. This can be a problem for glaciologists, too, since they rely on optical satellite imagery to study glacier area changes over the last decades (mainly Landsat). Clear-sky optical images can also be used to determine glacier velocity, albedo, front variations, etc.
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Monitoring the snow cover in ski resorts using Sentinel-2

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We are preparing the distribution of maps of the snow cover extent made from the Sentinel-2 data for Theia. If the method used to detect the snow is based on well-proven concepts, spatial and temporal resolution of the snow maps will however quite unprecedented. Until now, maps of the snow cover extent were usually produced from MODIS observations at 500 m resolution, which is adapted to hydro-climatic studies to rather regional scales. Landsat data were actually little exploited by snow scientists because of their low repeatability. The deployment of Sentinel-2 mission (global coverage at 20 m resolution every 5 days) opens new perspectives for monitoring snow cover.
 
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Suivi de l'enneigement des stations de ski avec Sentinel-2

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Dans le cadre du pôle thématique Theia nous préparons la distribution de cartes d'enneigement établies à partir des images Sentinel-2. Si la méthode utilisée pour la détection du manteau neigeux se base sur des concepts bien éprouvés, la résolution spatio-temporelle des cartes d'enneigement sera en revanche tout à fait inédite. Jusqu'ici les cartes d'enneigement était généralement produites à partir des observations MODIS à 500 m de résolution ce qui permet de faire des études hydro-climatiques à des échelles plutôt régionales. Les données Landsat étaient finalement assez peu exploitées par les nivologues en raison de leur faible répétitivité. Le déploiement de la mission Sentinel-2 (couverture globale à 20 m de résolution tous les 5 jours) ouvre de nouvelles perspectives pour le suivi de l'enneigement.
 
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