ICEFLOW: short-term movements in the Cryosphere

Bas Altena Department of Geosciences, University of Oslo. now at: Institute for Marine and Atmospheric research, Utrecht University. Bas Altena, project Iceflow geometric properties from optical remote sensing

Bas Altena, project Iceflow Sentinel-2 Fast flow through icefall

[published] Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on , . Journal of .

[outreach] see also ESA Sentinel Online: Copernicus Sentinel-2 monitors icefall, helping climbers ascend Mount Everest

Bas Altena, project Iceflow Sentinel-2 Fast flow through icefall

0 1 2 km glacier surface speed [meter/day] 0.2 0.4 0.6 0.8 1.0 1.2

Mt. Everest 300 1800 1200 600 0 2/4 right 0 5/4

4/4 left 4/4 2/4 R 3/4 L -300 terrain slope [deg] surface velocity contours Western Chm interval per 1/4 [meter/day] 10◦ 20◦ 30◦ 40◦

[outreach] see also Adventure Mountain: Mount Everest: The way the Khumbu Icefall flows

Bas Altena, project Iceflow Sentinel-2 Fast flow through icefall

∆H Ut=2000 U t=2020 H internal velocity profile

icefall α 2A  ∂H 3 U = − 3+2 H tan αρgH ∂x

MSc thesis research at Wageningen University

Bas Altena, project Iceflow Quantifying precision in velocity products

557 200 557 600 7 666 200 NCC 7 666 000 score 1 7 665 800 Θ 0.5 0

7 665 600 557 460 557 480 557 500 557 520 7 665 800 search space zoom in template/chip correlation surface 7 666 200 7 666 200

7 666 000 7 666 000

7 665 800 7 665 800

7 665 600 7 665 600

557 200 557 600 557 200 557 600

[submitted] Dispersion estimation of remotely sensed glacier displacements for better error propagation. The Cryosphere.

Bas Altena, project Iceflow Quantifying precision in velocity products

49.5◦E 49.0◦E 48.5◦E Radon orientation

0◦

◦ N 69.2 N 180◦ 10 km

1.0 Shear strain rate +1/16 69.1◦N 0.5 streamlines 0 5 km 10 km 0.0 0 -1 surface velocity [ m · d ] N 10 km 31.6 10.0 3.16 1.00 0.32 0.10 -1/16

[submitted] Dispersion estimation of remotely sensed glacier displacements for better error propagation. The Cryosphere.

Bas Altena, project Iceflow Monitoring river ice break-up

local equatorial crossing time [hh:mm] 14:00 Aqua Sentinel-3A

Sentinel-3B 13:00 spatial resolution coarse (500-100m) medium (100-10m) 12:00 high (10-3m)

11:00 Terra PROBA-V CBERS-4 Venµs entropy filter post processing final IRS 1C SPOT5IRS P6 Sentinel-2A displacements CBERS-1 CBERS-2 Sentinel-2 10:00 Landsat 8 Q Landsat 7 EO1 feature raw Dove 10m red locations displacements Flock-3P & 3P’ directional 9:00 1995 2000 2005 2010 2015 2020 filter

upsampling weights template 100m centerline & direction 30m Global River PROBA-V similarity score Widths from search space Landsat mathematical image matching morphology

[outreach] see also ESA Sentinel Online: Copernicus Sentinels observe vast and fast movements in the Arctic

Bas Altena, project Iceflow Monitoring river ice break-up

500 000 Zhigansk Kystatyam

100 km 600 000 N

ice speed [m/s] Kyusyur

700 000 0 1 2 3 x y 7 500 000 7 600 000 7 700 000 7 800 000 7 900 000 UTM [m]

[in review] Noticing river ice movement through a combination of European satellite monitoring services. International Journal of Applied Remote Sensing and Geo-information.

Bas Altena, project Iceflow Wiley book

bookchapter in Surface Displacement Measurement by Remote Sensing Imagery or Mesure de Deplacement´ de Surface par Imagerie de Tel´ ed´ etection´

Glaciology: Studying dynamics from remote sensing images.

Bas Altena, project Iceflow