Joe Mason

UW Madison Geography, opinions are mine. Geomorphology, soils, dunes, loess, in the Midwest, Great Plains, northern China. Living on Ho-Chunk lands

Joe Mason boosted:
2023-05-27

Surveying stream beds (and trash) earlier this week. I can’t wait to see how the surveys compare to the ones we did last summer, because my eyes tell me there were some changes at most of our sites. #FieldWorkFriday #FieldPhotoFriday #urbanStream #TrashyStreams

View of a total station, gravel bar, and brown man holding a reflector on a pile. Forest in background.
2023-03-08

Zooming in to show the dune forms that appear at different scales.

Zooming in on  large linear dunes of reddish brown sand; second photo shows smaller forms superimposed on these large ridges
2023-03-08

Sand drifting toward the Atlantic in beautiful, complex dunes, past the Richat Structure. Mauretania and Western Sahara. #Sentinel2, Feb 25, 2023

Satellite image showing reddish sands of the Sahara drifting past a concentric rock structure. Atlantic ocean visible on the west side.
2023-02-12

Same perspective on the same landscape, but with stream network generated by DepressionBreach and StreamExtract in #Whitebox Tools, virtually identical the r.watershed result. Part of an effort to characterize drainage networks on these landscapes and compare them to results of landscape evolution modeling

3D perspective view of a landscape with a large depression and dissected slopes around it. Lines show stream network generated by Whitebox Tools
2023-02-12

Perspective view of a loess landscape in central Nebraska, with large closed wind-eroded depressions surrounded by stream-dissected terrain. Topography from 1 m #lidar DEM. Blue lines are the stream network generated by the r.watershed tool in GRASS GIS, not entirely realistic but better than many other algorithms for this, it seems. Note effects of road embankments, ditches, and field terraces, all captured by lidar data.

3D perspective view of a landscape with a large depression and dissected slopes around it. Lines show stream network generated by r.watershed tool
2023-02-09

Thick loess southwest of Broken Bow, Nebraska, sculpted by wind erosion and dissected by streams. Previous research shows coarse late Pleistocene loess in this region can be directly entrained by winds below the threshold for aeolian sand mobility. Troughs and narrow ridges are oriented NW-SE, typical of all large-scale deflation features in Central Plains loess. 3D perspectives created with #rayshader

Three-dimensional perspective view of complex topography eroded in loess by wind and waterThree-dimensional perspective closeup of part of the area shown in the other image
2023-01-16

Sediment plume from the Russian River, northern California, January 9, 2023. Sentinel 2 image.

Satellite image shows a coastline with scattered clouds over land areas. There is a large tan colored sediment plume forming rounded lobes in the dark ocean water
2023-01-15

@Brad_Rosenheim 2100 by 1340 meters (2 m DEM)

2023-01-15

Taking a careful look at a small loess table, in the Loess Canyons area of southwest Nebraska. #rayshader

2023-01-04

Same area and images, zoomed out. A swath of fully active dunes is south of the river, with vegetation-stabilized dunes on either side.

Same September image of the Yellow at high flow and sediment-laden. Bright colored swath of active dunes visible south of the riverSame area with river dry and fields tan-colored in early January
2023-01-04

Yellow River in the desert, full of water and sediment from the summer monsoon on 9/5/2022 and virtually dry on 1/3/2023. Just west of Baotou, Inner Mongolia, in the northern bend of the river. I think the whitish areas in the dry January image are areas where soluble salts have precipitated at the surface after irrigation ended for the season (common in dry regions where there's a shallow water table). Sentinel 2 image. Marker at 109.30,40.47. Zoomed out view in reply.

Satellite image of wide river with intense reddish brown color flowing through green irrigated landSatellite image of same are in early January, river is mostly dry, fields are tan not green
2023-01-02

Yellow River delta and sediment plume, 9/5/2020, carrying sediment mobilized in the summer monsoon, including lots of eroded loess. Sentinel 2 image viewed in GEE

Satellite image shows highly sediment-laden Yellow River flowing onto its delta and producing a plume of yellowish brown sediment that contrasts with dark greenish blue ocean water
2022-12-31

Now zoomed in on the Fraser River sediment plume, at the river mouth just south of Vancouver, B.C.

Satellite image showing light-colored plume of sediment carried into dark-toned ocean water by the Fraser River, British Columbia. Fraser delta in upper right
2022-12-31

Fraser River sediment plume, 6/24/2022. First a regional view. What a beautiful image.

Regional view in a satellite image. Shows snow-capped mountains of southern British Columbia and northern Washington, Fraser River valley with farmland, sediment plume, and Vancouver Island to the west
2022-12-25

Closer look at ice on lakes Mendota and Monona, yesterday.

Satellite image shows patterns in ice on Lake Monona, including ridges and linear gaps with open waterZoomed in satellite image showing most of Lake Mendota with partial ice cover, centered on Picnic Point
2022-12-25

Ice on the Madison lakes, yesterday. Sentinel 2 image.

Satellite image of Madison, Wisconsin are with ice on Lakes Mendota, Monona, and Wingra
2022-12-22

2. Highway 61 Revisited. Along the Mississippi River in southeastern Minnesota.

View from a snow plow, partly snow-covered highway, Mississippi River on the left, rock bluff on the right
2022-12-22

Watch the storm on Minnesota's plowcams:

1. Out on Highway 61, North Shore of Lake Superior near Grand Portage.

View from snow plow on a partly snow-covered highway, forest on each side
Joe Mason boosted:
2022-12-21

Pleistocene glacial striations on Devonian and Neoproterozoic rock in New England. Savin Hill, Middlesex Fells, and Mt Monadnock. See captions for details.

#rocks #glaciology #Boston #MiddlesexFells #MountMonadnock #sedimentary #Medford #Neoproterozoic #Devonian #Pleistocene

Pleistocene glacial striations on the Devonian Littleton Formation on Mt Monadnock, New Hampshire USA. Sediments were deformed in the Acadian Orogeny, about 400 Ma. Striations angle from top left to bottom right, cutting across a joint with grass growing in it. Photo by me.Pleistocene glacial polish and striations on the Neoproterozoic Roxbury Conglomerate, Savin Hill, Boston, Massachusetts USA. Roxbury is interpreted to have been part of the peri-Gondwana Avalon Terrane. Cobbles are polished, not fractured. My photo.Pleistocene glacial striations from lower left to upper right, on the Neoproterozoic Lynn Volcanics, near Wright’s Tower, Middlesex Fells, Medford, Massachusetts (just north of Boston), USA. Compass (a bit bigger than a credit card) shows direction from NNW to SSE, as expected. Lynn Volcanics are interpreted to have been part of the peri-Gondwana Avalon Terrane, and probably equivalent to the Mattapan Formation exposed south of Boston. My photo.
2022-12-21

Very interesting review paper. Loess is coarse dust by the definition used here, transported relatively short distances. This review is mostly about longer distance and higher level coarse dust transport, more important than previously recognized and not very well represented in models.

twitter.com/DrYemiAdebiyi/stat

doi.org/10.1016/j.aeolia.2022.

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