The Souness Martian glacier-like forms - looking at the lowest and highest elevation objects

Colin Souness, in his 2012 paper listed a total of 1309 'glacier-like forms' on the surface of Mars, in the mid-latitudes centred around 40° latitude, found from Mars Reconnaisance Orbiter context camera images.

In my dissertation (version for tablets) I studied descriptive statistics of them, including the distribution by elevation.

Since then, I have produced a web index to the objects, including a Top Trumps page for each object. I below show a table of links to the 30 Souness objects at the lowest and highest elevations. The Mars Express High Resolution Stereo Camera digital terrain model tile is shown where there is coverage, and it is also indicated where there are HiRISE images, or 3d anaglyphs that intersect with the outline of the object. These are linked to from the Top Trump page.

The elevation distribution looks as follows:

Elevation histograms for Souness object extents and head areas, compared with the overall elevation distribution in the coverage of the HRSC DTM tiles used

Slope histograms for Souness object extents and head areas, compared with the overall slope distribution in the coverage of the HRSC DTM tiles used

Showing the ratio of the GLF distribution as a function of elevation and slope / elevation and slope distribution in the HRSC tiles for extents.

The GLF distribution as a function of elevation  / elevation distribution in the HRSC tiles for the head areas.

The GLF distribution as a function of slope  / slope distribution in the HRSC tiles for the head areas.

I noted in the dissertation that that the numbers of glaciers appeared to be depleted below elevations of -3000m relative to Mars datum. There are two types of explanation for this, firstly that they were not formed, or secondly that they were more rapidly ablated. Fewer may have formed in the range -5000 to -3000 due to slope effects, with a large proportion of the these elevations being made up of the flat plains in the northern hemisphere, and the Martian glaciers are preferentially found on slopes. Alternatively in the higher-obliquity epoch, ablation may have been favoured at low elevations, due to higher temperatures, and possibly wind-stripping of debris cover allowing sublimation.


The outliers at the extreme ends of the elevation distribution may be of interest, since they may show something about what limited the distribution of Souness objects on Mars.

There is a secondary peak in the distribution at very low elevations. These could have formed at a later epoch at a lower obliquity in a cooler climate where glacier accumulation was only significant at the lowest elevations.
It is also an interesting question whether the objects at very high elevations formed at the same epoch as the main distribution, or whether these come from an older, more extreme obliquity epoch.

Lowest and highest 30 Souness glacier-like forms

Based on mean elevation of 5km circular radius buffer (from Souness et al. 2012 paper)

Lowest elevation 30 GLFs (buffer mean from Souness catalog):

Catalog number	Elevation (m)	Region	HRSC DTM tile	Centre Latitude	Centre Longitude	Area (sq. km)	N HiRISE footprints intersecting	N anaglyphs intersecting
1130	-6664	West of Hellas	H2613_0000	-32.51	56.61	5.63	0	0
1123	-6603	East of Hellas	none	-35.62	75.61	0.80	0	0
1126	-6540	West of Hellas	none	-30.82	64.50	0.71	0	0
1119	-6534	East of Hellas	H2195_0000	-44.29	83.56	2.85	0	0
1122	-6533	East of Hellas	none	-35.56	75.58	0.79	0	0
1120	-6466	East of Hellas	H2195_0000	-44.30	83.57	2.92	0	0
1118	-6001	East of Hellas	H2631_0001	-42.71	85.99	1.35	0	0
1301	-5507	East of Hellas	H2631_0001	-39.82	86.16	0.75	0	0
1302	-5456	East of Hellas	H2631_0001	-39.82	86.14	0.84	1	0
193	-5431	Utopia Planitia and Phlegra Montes	none	38.59	137.20	1.03	1	0
1117	-5334	East of Hellas	H2631_0001	-39.82	86.16	0.70	0	0
1114	-5283	East of Hellas	H2609_0000	-38.22	88.12	2.24	0	0
1300	-5227	East of Hellas	H2631_0001	-39.82	86.17	18.47	0	0
198	-5137	Utopia Planitia and Phlegra Montes	H1526_0000	38.93	116.36	1.99	3	1
200	-5108	Utopia Planitia and Phlegra Montes	H1526_0000	39.08	116.07	3.62	1	0
1112	-5097	East of Hellas	H0365_0000	-40.97	90.17	2.05	1	0
1113	-5077	East of Hellas	H0365_0000	-40.99	90.16	0.61	1	0
194	-5025	Utopia Planitia and Phlegra Montes	H2878_0000	40.12	120.16	1.96	1	0
199	-5019	Utopia Planitia and Phlegra Montes	H1526_0000	39.05	116.05	0.59	1	0
195	-5008	Utopia Planitia and Phlegra Montes	H2878_0000	40.11	120.23	2.64	1	0
1115	-4981	East of Hellas	H2609_0000	-38.21	88.06	4.74	0	0
196	-4958	Utopia Planitia and Phlegra Montes	H2878_0000	40.58	120.39	8.78	0	0
1111	-4886	East of Hellas	H0365_0000	-40.62	90.28	3.07	0	0
197	-4881	Utopia Planitia and Phlegra Montes	H2878_0000	40.52	120.53	6.11	0	0
1116	-4860	East of Hellas	H2609_0000	-38.62	87.94	8.01	0	0
1131	-4842	West of Hellas	none	-35.20	51.26	8.64	0	0
1103	-4588	East of Hellas	H0528_0000	-38.54	94.37	2.00	2	1
1134	-4193	West of Hellas	none	-35.61	48.98	2.14	0	0
1110	-4187	East of Hellas	H0550_0000	-36.51	90.17	0.84	0	0
3	-4161	Deuteronilus Mensae	H3253_0000	38.33	-9.76	2.41	0	0

Highest elevation 30 GLFs (buffer mean from Souness catalog):

Catalog number	Elevation (m)	Region	HRSC DTM tile	Centre Latitude	Centre Longitude	Area (sq. km)	N HiRISE footprints intersecting	N anaglyphs intersecting
844	7681	Tharsis	H0453_0000	-40.65	-92.24	9.01	1	0
845	6928	Tharsis	H0266_0000	-40.91	-94.50	0.93	0	0
846	6784	Tharsis	H0266_0000	-40.93	-94.52	0.88	0	0
848	6708	Tharsis	H0266_0000	-40.95	-94.58	1.44	0	0
847	6662	Tharsis	H0266_0000	-40.95	-94.56	1.60	0	0
82	5894	Olympus Mons and surrounding area	none	41.69	-110.67	1.16	0	0
850	5407	Tharsis	H0508_0000	-40.90	-97.60	1.00	0	0
849	5301	Tharsis	H0508_0000	-40.81	-97.94	0.81	0	0
851	5101	Tharsis	H0508_0000	-40.92	-97.49	1.02	0	0
852	4556	Tharsis	H0508_0000	-41.85	-97.55	1.22	1	0
853	4445	Tharsis	H0508_0000	-41.86	-97.49	1.13	1	0
81	4139	Olympus Mons and surrounding area	H5405_0000	44.92	-111.19	3.29	0	0
827	4101	Tharsis	H4087_0000	-35.01	-79.64	1.01	0	0
79	3927	Olympus Mons and surrounding area	none	38.33	-103.58	0.67	1	0
823	3799	Tharsis	H2596_0001	-35.48	-75.24	4.97	0	0
818	3769	Tharsis	none	-36.62	-70.77	4.20	1	0
854	3762	Tharsis	none	-42.32	-98.61	0.84	0	0
866	3675	Tharsis	H4234_0000	-42.08	-124.73	7.10	0	0
817	3626	Tharsis	none	-36.60	-70.54	4.60	1	0
1034	3533	East of Hellas	H2356_0002	-40.83	103.02	20.49	2	1
794	3475	Argyre	none	-50.59	-58.61	10.56	0	0
1287	3444	East of Hellas	H2279_0001	-42.76	108.15	9.71	0	0
825	3441	Tharsis	H2607_0000	-41.95	-76.95	1.47	0	0
819	3433	Tharsis	none	-36.61	-70.47	1.57	1	0
764	3404	Argyre	H2669_0000	-38.90	-48.01	3.90	1	0
859	3210	Tharsis	H2644_0000	-49.59	-113.36	8.60	0	0
824	3196	Tharsis	H2640_0000	-41.49	-77.02	13.87	1	0
862	3188	Tharsis	H0424_0000	-43.42	-121.98	4.31	0	0
1043	3155	East of Hellas	H0451_0000	-37.89	103.38	17.29	2	1
998	3134	East of Hellas	H1887_0000	-42.03	109.59	38.62	0	0

Based on mean HRSC DTM elevation of immediate head area (100m radius)

Lowest elevation 30 GLFs (head):

Note that a terminus elevation of 0 is due to the terminus falling in a no data area.

Catalog number	Head elevation (m)	Termimus elevation (m)	Region	HRSC DTM tile	Head Latitude	Head Longitude	Area (sq. km)	N HiRISE footprints intersecting	N anaglyphs intersecting
1130	-6858	-7173	West of Hellas	H2613_0000	-32.50	56.65	5.63	0	0
1119	-6667	-6943	East of Hellas	H2195_0000	-44.27	83.58	2.85	0	0
1120	-6639	-6918	East of Hellas	H2195_0000	-44.30	83.60	2.92	0	0
1118	-5779	-6047	East of Hellas	H2631_0001	-42.70	85.99	1.35	0	0
1117	-5550	-5647	East of Hellas	H2631_0001	-39.83	86.17	0.70	0	0
1301	-5550	-5663	East of Hellas	H2631_0001	-39.83	86.16	0.75	0	0
1302	-5430	-5659	East of Hellas	H2631_0001	-39.84	86.13	0.84	1	0
198	-5251	-5718	Utopia Planitia and Phlegra Montes	H1526_0000	38.90	116.38	1.99	3	1
1300	-5180	-5595	East of Hellas	H2631_0001	-39.21	86.18	18.47	0	0
1113	-5050	0	East of Hellas	H0365_0000	-40.99	90.17	0.61	1	0
200	-4996	-5782	Utopia Planitia and Phlegra Montes	H1526_0000	39.08	116.04	3.62	1	0
1115	-4937	-5051	East of Hellas	H2609_0000	-38.19	88.07	4.74	0	0
1112	-4934	0	East of Hellas	H0365_0000	-40.97	90.19	2.05	1	0
199	-4927	-5397	Utopia Planitia and Phlegra Montes	H1526_0000	39.05	116.04	0.59	1	0
1114	-4912	-5228	East of Hellas	H2609_0000	-38.22	88.10	2.24	0	0
1116	-4861	-5262	East of Hellas	H2609_0000	-38.65	87.98	8.01	0	0
1111	-4775	-5282	East of Hellas	H0365_0000	-40.61	90.25	3.07	0	0
1103	-4691	-5009	East of Hellas	H0528_0000	-38.55	94.34	2.00	2	1
1	-4222	-4534	Deuteronilus Mensae	H5314_0000	37.89	-5.93	10.95	3	1
2	-4149	-4530	Deuteronilus Mensae	H5314_0000	37.99	-5.96	18.95	3	1
1110	-4037	-4049	East of Hellas	H0550_0000	-36.50	90.18	0.84	0	0
6	-3805	-4014	Deuteronilus Mensae	H1498_0000	30.59	-11.34	2.79	1	0
192	-3772	-4407	Utopia Planitia and Phlegra Montes	H1317_0000	34.24	144.32	4.39	2	0
3	-3746	-4196	Deuteronilus Mensae	H3253_0000	38.32	-9.78	2.41	0	0
120	-3691	-3845	Olympus Mons and surrounding area	H1258_0001	34.22	-177.33	4.71	0	0
121	-3684	-4010	Olympus Mons and surrounding area	H1258_0001	34.22	-177.33	6.58	0	0
4	-3677	-3914	Deuteronilus Mensae	H3253_0000	38.27	-9.31	1.35	0	0
5	-3604	-4058	Deuteronilus Mensae	H3253_0000	40.04	-10.36	2.50	0	0
299	-3447	-3681	Nilosyrtis Mensae	H1629_0000	42.47	62.49	1.40	0	0
1299	-3393	-4112	East of Hellas	H0550_0000	-35.30	91.18	1.65	7	1

Highest elevation 30 GLFs (head):

Catalog number	Head elevation (m)	Termimus elevation (m)	Region	HRSC DTM tile	Head Latitude	Head Longitude	Area (sq. km)	N HiRISE footprints intersecting	N anaglyphs intersecting
844	7484	7166	Tharsis	H0453_0000	-40.63	-92.20	9.01	1	0
848	7078	6647	Tharsis	H0266_0000	-40.94	-94.59	1.44	0	0
847	6980	6616	Tharsis	H0266_0000	-40.94	-94.57	1.60	0	0
845	6971	6730	Tharsis	H0266_0000	-40.90	-94.51	0.93	0	0
846	6959	6679	Tharsis	H0266_0000	-40.92	-94.53	0.88	0	0
849	5624	5096	Tharsis	H0508_0000	-40.80	-97.93	0.81	0	0
850	5439	4826	Tharsis	H0508_0000	-40.88	-97.60	1.00	0	0
851	5190	4766	Tharsis	H0508_0000	-40.91	-97.49	1.02	0	0
852	4822	4204	Tharsis	H0508_0000	-41.83	-97.55	1.22	1	0
853	4566	4025	Tharsis	H0508_0000	-41.84	-97.50	1.13	1	0
827	4183	3695	Tharsis	H4087_0000	-35.00	-79.64	1.01	0	0
81	3914	3587	Olympus Mons and surrounding area	H5405_0000	44.91	-111.21	3.29	0	0
866	3797	3217	Tharsis	H4234_0000	-42.05	-124.71	7.10	0	0
823	3729	3628	Tharsis	H2596_0001	-35.44	-75.27	4.97	0	0
1287	3634	1951	East of Hellas	H2279_0001	-42.82	108.19	9.71	0	0
764	3627	2737	Argyre	H2669_0000	-38.89	-48.06	3.90	1	0
825	3529	2918	Tharsis	H2607_0000	-41.93	-76.97	1.47	0	0
1043	3367	752	East of Hellas	H0451_0000	-37.81	103.39	17.29	2	1
862	3317	2847	Tharsis	H0424_0000	-43.40	-121.99	4.31	0	0
859	3249	1968	Tharsis	H2644_0000	-49.55	-113.33	8.60	0	0
1034	3225	-175	East of Hellas	H2356_0002	-40.70	103.01	20.49	2	1
863	3100	2827	Tharsis	H0424_0000	-43.42	-122.02	4.36	0	0
826	3042	2691	Tharsis	H2607_0000	-41.92	-76.89	2.57	0	0
1290	3013	1087	East of Hellas	H2356_0002	-41.71	104.12	21.98	1	0
822	2939	2606	Tharsis	H2596_0001	-37.19	-72.32	0.92	0	0
824	2926	2282	Tharsis	H2640_0000	-41.48	-77.12	13.87	1	0
861	2892	2332	Tharsis	H2197_0001	-51.24	-113.67	2.04	0	0
1042	2825	1510	East of Hellas	H0451_0000	-37.83	103.32	4.63	2	1
1015	2800	569	East of Hellas	H2345_0000	-44.83	104.75	15.26	2	0
763	2780	2162	Argyre	H2669_0000	-38.54	-48.03	1.12	0	0