It would get your attention if the younger ice were peeled off and a 1000 m tower of unexpected ice were revealed, dwarfing the tallest skyscraper in Dubai (Burj Khalifa, 830 m)? Maybe if you saw the whole 80 km ridge, of which the tower is only a representative slice.
Overflights orthogonal to contemporary flow have a quasi twofold symmetry centered on each feature whereas (next post or so) flights parallel to flow do not have this symmetry but lopsided nested lobes instead, on the downhill side that suggest extensional flow in that direction. In the Petermann Grid upheaval zone, there are no significant deflections attributable to bedrock because it is too featureless. (No upheavals are located over the Grand Canyon.)
Although the ice was laid down in sedimentary layers, I'm not completely thrilled with use of rock geology terms (anticlines, synclines, recumbent folds, sheath folds) to describe ice deformations. There may be a better analogy to gravity-driven salt bed flow (eg Paradox Formation, US) though dissolution of salt by water does not quite correspond to ice melt.
I'm beginning to wonder if we almost lost the Greenland Ice Sheet during the Eemian. I'm not seeing the slightest hint of deformations in more recent layers. There have back-and-forth views on how much of the sea level should be attributed to Antarctica. These views affect allocation of research resources.
I've annotated various features in the last frame of the animation. The vertical exaggeration is about 10x. May have to click to see it run at full size. A portion at 2x enlargement is shown in the second image. As usual, things look quite different at 1:1 scale (third image).
The fourth image shows one-off diagonal transects from other years. It's really difficult for me to imagine how any working Greenland glaciologist then or now could be unaware of the 1997-99 overflights. Zachariae is also significantly impacted.
For the convenience of this yet-to-surface bright undergraduate, I sorted through the entire Cresis archive for flight segment names relevant to studying the Petermann Grid -- these can be grepped into a kml file that Google Earth will load in one step.
Some of these are just flanking layer cake needed to define upheaval volume (see preceding post). It's important to recall that NEEM drilled through a double fold that cannot be seen on radar, probably for lack of adequate reflectors. It follows that upheavals must be far more widespread than what we currently can see:
20100324_01_007, 20100324_01_008, 20100324_01_009, 20100324_01_010, 20100324_01_011, 20100324_01_012, 20100324_01_013, 20100324_01_014, 20100324_01_015, 20100324_01_016, 20100324_01_017, 20100324_01_018, 20100324_01_019, 20100324_01_020, 20100324_01_021, 20100324_01_022, 20100324_01_023, 20100324_01_024, 20100324_01_025, 20100324_01_026, 20100324_01_027, 20100324_01_028, 20100324_01_029, 20100324_01_030, 20100324_01_031, 20100324_01_032, 20100324_01_033, 20100324_01_034, 20100324_01_035, 20100324_01_036, 20100324_01_037, 20100324_01_038, 20100324_01_039, 20100324_01_040, 20100324_01_041, 20100324_01_042, 20100324_02_001, 20100324_02_002, 20100324_03_001, 20100324_03_002, 20100324_04_001, 20110429_01_001, 20110429_01_009, 20110429_01_010, 20110429_01_011, 20110429_01_012, 20110429_01_013, 20110429_01_014, 20110429_01_015, 20110429_01_016, 20110429_01_017, 20110429_01_018, 20110429_01_019, 20110429_01_020, 20110429_01_021, 20110429_01_022, 20110429_01_023, 20110429_01_024, 20110429_01_025, 20110429_01_026, 20110429_01_027, 20110429_01_028, 20110429_01_029, 20110429_01_030, 20110429_01_031, 20110429_01_032, 20110429_01_033, 20110429_01_034, 20110429_02_001, 20110429_02_002, 20110429_02_003, 20110429_02_004, 20110429_02_005, 20110429_02_006, 20110429_02_007, 20110429_02_008, 20110429_02_009, 20110429_02_010, 20110429_02_011, 20110429_02_012, 20110429_02_013, 20110429_02_014, 20110429_02_015, 20110429_02_016, 20110429_02_017, 20110429_02_018, 20110429_02_019, 20110429_02_020, 20110429_02_021, 20110507_01_011, 20110507_01_012, 20110507_01_013, 20110507_01_014, 20110507_01_015, 20110507_01_016, 20110507_01_017, 20110507_01_018, 20110507_01_019, 20110507_01_020, 20110507_01_021, 20110507_01_022, 20110507_01_023, 20110507_01_024, 20110507_01_025, 20110507_01_026, 20110507_01_027, 20110507_01_028, 20110507_01_029, 20110507_01_030, 20110507_01_031, 20110507_01_032, 20110507_01_033, 20110507_01_034, 20110507_01_035, 20110507_01_036, 20110507_01_037, 20110507_01_038, 20110507_02_001, 20110507_02_002, 20110507_02_003, 20110507_02_004, 20110507_02_005, 20110507_02_006, 20110507_02_007, 20110507_02_008, 20110507_02_009, 20110507_02_010, 20110507_02_011, 20110507_02_012, 20110507_02_013, 20110507_02_014, 20110507_02_015, 20110507_02_016, 20110507_02_017, 20110507_02_018, 20110507_02_019, 20110507_02_020, 20110507_02_021, 20110507_02_022
Flight segment names for diagonals to the Grid:
19970527_01_003, 19970527_01_004, 19970527_01_009, 19970527_01_019, 19970528_01_005, 19970528_01_006, 19970528_01_009, 19970528_01_010, 19970528_01_011, 19990507_01_003, 19990507_01_004, 19990507_01_015, 19990507_01_016, 19990510_01_014, 19990510_01_015, 19990510_01_016, 19990511_01_003, 19990511_01_004, 19990511_01_006, 19990511_01_007, 19990511_01_013, 19990511_01_014, 19990511_01_015, 19990512_01_002, 19990512_01_003, 19990512_01_019, 19990513_01_002, 19990513_01_003, 19990514_01_023, 19990517_01_008, 19990517_01_009, 19990517_01_010, 19990519_01_022, 19990525_01_022, 20030513_01_019, 20030513_01_020, 20110502_01_010, 20110502_01_011, 20110502_01_012, 20110502_02_024, 20110502_02_025, 20110502_02_026, 20110509_01_011, 20110509_01_012, 20110509_01_013, 20120503_03_056, 20120503_03_057, 20120503_03_058, 20120503_03_059, 20120514_01_016, 20120514_01_017, 20120514_01_018, 20120514_01_019, 20120514_01_020, 20120514_02_045, 20120514_02_046, 20120514_02_047, 20120514_02_048, 20120514_02_049, 20120514_02_050, 20120514_02_051, 20120514_02_052, 20120516_01_014, 20120516_01_015, 20120516_01_016, 20120516_01_017, 20120516_01_018, 20120516_01_076, 20120516_01_077, 20120516_01_078, 20120516_01_079, 20120516_01_080, 20130426_01_011, 20130426_01_012, 20130426_01_013