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Table 1 Selected historical accounts reporting on the presence of snow in the Marrakech High Atlas Marrakech High Atlas and a ridge extends over 5 km linking these 4000 m peaks (Fig. 11). Three well-developed cirques are present on the east of this ridge and have well-developed NE-facing cirques and they support late-lying snow and con- tain well-developed moraines, some of the highest moraines of the Marrakech High Atlas (Fig. 11). profile development index values clearly separate differ- ent moraine surfaces and the youngest moraines around the Névé Permanent have almost no soil development. These were moraines correlated with the Little Ice Age in Hughes (2014), which is consistent with the data of Han- nah et al. (2017).

Table 1 Selected historical accounts reporting on the presence of snow in the Marrakech High Atlas Marrakech High Atlas and a ridge extends over 5 km linking these 4000 m peaks (Fig. 11). Three well-developed cirques are present on the east of this ridge and have well-developed NE-facing cirques and they support late-lying snow and con- tain well-developed moraines, some of the highest moraines of the Marrakech High Atlas (Fig. 11). profile development index values clearly separate differ- ent moraine surfaces and the youngest moraines around the Névé Permanent have almost no soil development. These were moraines correlated with the Little Ice Age in Hughes (2014), which is consistent with the data of Han- nah et al. (2017).

Related Figures (13)

Fig. 1 Location map showing the maximum extents of Pleistocene glaciers in the High Atlas. Modified from Hughes et al. (2018) and Hughe et al. (2020). Contours are at 100 m intervals
Fig. 1 Location map showing the maximum extents of Pleistocene glaciers in the High Atlas. Modified from Hughes et al. (2018) and Hughe et al. (2020). Contours are at 100 m intervals
list is not exhaustive but highlights the most prominent and repeat- ing late-lying snow and ice patches based on the most recent observa- tions. No glaciers survive today in the Marrakech High Atlas Fig. 2 Location maps showing the positions of current late-lying snowpatches in the Marrakech High Atlas. Sites of late-lying snow and ice patches earlier in the Holocene, including the 20th Century and the Little Ice Age, are likely to be much more widespread. This
list is not exhaustive but highlights the most prominent and repeat- ing late-lying snow and ice patches based on the most recent observa- tions. No glaciers survive today in the Marrakech High Atlas Fig. 2 Location maps showing the positions of current late-lying snowpatches in the Marrakech High Atlas. Sites of late-lying snow and ice patches earlier in the Holocene, including the 20th Century and the Little Ice Age, are likely to be much more widespread. This
Fig.3 A Walter and Lieth (1967) diagram of the climate of Mar- rakech. Data from CRU TS v4.03 (Harris et al. 2014) for the period 1901-2018
Fig.3 A Walter and Lieth (1967) diagram of the climate of Mar- rakech. Data from CRU TS v4.03 (Harris et al. 2014) for the period 1901-2018
Fig.4 Climate data for Marrakech from CRU TS v4.03 (Harris et al. 2014) for the period 1901-2018. a Mean annual temperature, (b) Mean summer temperature, (c) Total annual precipitation, (d) Total winter precipitation. Dotted lines show mean for the entire period, while the dark grey line shows the trend
Fig.4 Climate data for Marrakech from CRU TS v4.03 (Harris et al. 2014) for the period 1901-2018. a Mean annual temperature, (b) Mean summer temperature, (c) Total annual precipitation, (d) Total winter precipitation. Dotted lines show mean for the entire period, while the dark grey line shows the trend
Fig.5 Mean annual precipitation in the Marrakech High Atlas, showing highly variable inter-annual precipitation recorded at three sites spanning a 1500 m altitudinal gradient. Although precipitation amounts vary, they show a consistent pattern of precipitation declin- ing in the area since the 1970s: Agaiouar (31.28, — 7.82, 1805 ma.s.1, 1930-1997); Aghbalou (31.32, — 7.75, 1070 m a.s.l, 1969-2014); Oukaimeden (31.20, — 7.85, 2600 m a.s.1., 1989-2007) fine-grained matrix of the sediment ridge is consistent witt subglacial abrasion and clast crushing under a dynamic ice mass rather than a static snow or ice patch. However, this is not always conclusive since sub-nival erosion, includins the production of striations on clasts, has been observed ir seasonal snowpatches (Carrera G6mez and Valcarcel Diaz 2013). Nevertheless, a glaciological approach supports the interpretations of the Tazaghart site as a former dynamic ice mass (see Hannah et al. 2017). The distance from the outermost parts of the bounding ridges to the break of slope at the cliff face is > 150 m. Modelling of threshold condi- tions for the formation of dynamic ice or firn indicates tha the maximum distance between a protalus rampart anc the talus foot upslope cannot exceed 30-70 m (Ballantyne and Benn 1994). The ice mass that produced the bounding ridges would have covered a total area of c. 1.49 hectare: (14,906 m?) and had an altitudinal range of 3320-3440 m The total area of ice may have reached > 2 hectares if the gully above up to 3800 m is included. Despite its relatively small size, the depth of the hollow enclosed by the ridges is > 30 m. Small glaciers have been observed covering jus 1-5 hectares (0.01-0.05 km”) in marginal settings in othe Mediterranean mountains (e.g. Grunewald and Scheithaue: 2010; Hughes 2009, 2010). In September 2012 the snow. patch was over 6 times smaller than this and covered ar area of just 0.2345 hectares (2345 m’) (Hannah et al. 2017) In September 2019 the lower part of Névé Permanent wa: slightly larger in size than in September 2012 with an are< of 2540 m?. The lowest altitude of the snowpatch in Sep. tember 2019 was measured using a GPS at 3346 m anc cross-checked on a topographic map. In April 2012, snow completely filled the area between the moraine crests below the current long-lying snowpatch (Fig. 10). Based on the height of the sediment ridges from the intervening gully the
Fig.5 Mean annual precipitation in the Marrakech High Atlas, showing highly variable inter-annual precipitation recorded at three sites spanning a 1500 m altitudinal gradient. Although precipitation amounts vary, they show a consistent pattern of precipitation declin- ing in the area since the 1970s: Agaiouar (31.28, — 7.82, 1805 ma.s.1, 1930-1997); Aghbalou (31.32, — 7.75, 1070 m a.s.l, 1969-2014); Oukaimeden (31.20, — 7.85, 2600 m a.s.1., 1989-2007) fine-grained matrix of the sediment ridge is consistent witt subglacial abrasion and clast crushing under a dynamic ice mass rather than a static snow or ice patch. However, this is not always conclusive since sub-nival erosion, includins the production of striations on clasts, has been observed ir seasonal snowpatches (Carrera G6mez and Valcarcel Diaz 2013). Nevertheless, a glaciological approach supports the interpretations of the Tazaghart site as a former dynamic ice mass (see Hannah et al. 2017). The distance from the outermost parts of the bounding ridges to the break of slope at the cliff face is > 150 m. Modelling of threshold condi- tions for the formation of dynamic ice or firn indicates tha the maximum distance between a protalus rampart anc the talus foot upslope cannot exceed 30-70 m (Ballantyne and Benn 1994). The ice mass that produced the bounding ridges would have covered a total area of c. 1.49 hectare: (14,906 m?) and had an altitudinal range of 3320-3440 m The total area of ice may have reached > 2 hectares if the gully above up to 3800 m is included. Despite its relatively small size, the depth of the hollow enclosed by the ridges is > 30 m. Small glaciers have been observed covering jus 1-5 hectares (0.01-0.05 km”) in marginal settings in othe Mediterranean mountains (e.g. Grunewald and Scheithaue: 2010; Hughes 2009, 2010). In September 2012 the snow. patch was over 6 times smaller than this and covered ar area of just 0.2345 hectares (2345 m’) (Hannah et al. 2017) In September 2019 the lower part of Névé Permanent wa: slightly larger in size than in September 2012 with an are< of 2540 m?. The lowest altitude of the snowpatch in Sep. tember 2019 was measured using a GPS at 3346 m anc cross-checked on a topographic map. In April 2012, snow completely filled the area between the moraine crests below the current long-lying snowpatch (Fig. 10). Based on the height of the sediment ridges from the intervening gully the
Sites of permanent snow and ice patches earlier in the Holocene, including the 20th Century and the Little Ice Age, are likely to be much more widespread. This list is not exhaustive but highlights the most promi- nent and repeating late-lying snow and ice patches based on the most recent observations. No glaciers sur- vive today in the Marrakech High Atlas
Sites of permanent snow and ice patches earlier in the Holocene, including the 20th Century and the Little Ice Age, are likely to be much more widespread. This list is not exhaustive but highlights the most promi- nent and repeating late-lying snow and ice patches based on the most recent observations. No glaciers sur- vive today in the Marrakech High Atlas
Little Ice Age moraine and pronival ramparts ridges are pre- sent in the northern valleys and cirques of Aksoual (3912 m) and Bou Iguenouane (3877 m) in the Imenane Valley (Fig. 12). In most valleys and cirques three moraine units are present, with the upper unit dating to the Late-glacial. For example, in the Irhzer Likemt valley moraines between 2975 Fig.6 Photograph of the Tazaghart Névé Permanent in September 2019 (photograph by Philip Hughes)
Little Ice Age moraine and pronival ramparts ridges are pre- sent in the northern valleys and cirques of Aksoual (3912 m) and Bou Iguenouane (3877 m) in the Imenane Valley (Fig. 12). In most valleys and cirques three moraine units are present, with the upper unit dating to the Late-glacial. For example, in the Irhzer Likemt valley moraines between 2975 Fig.6 Photograph of the Tazaghart Névé Permanent in September 2019 (photograph by Philip Hughes)
moraines, it is possible that some of these highest moraine/ pronival units are Holocene in age. On Bou Iguenouane a high-level cirque is also present on the eastern slopes and a series of moraines enclose some of the latest-lying snow of this area. Snow was absent from all areas of Aksoual and Bou Iguenouane in October 2013. On the NW face of Aksoual the northern cliffs of the ridge of Azrou n’Tamadot represent one of the largest cliff faces in the Atlas Mountains rising 1500 m inc. 2 km. A potential fourth moraine unit (not marked in Fig. 12) is
moraines, it is possible that some of these highest moraine/ pronival units are Holocene in age. On Bou Iguenouane a high-level cirque is also present on the eastern slopes and a series of moraines enclose some of the latest-lying snow of this area. Snow was absent from all areas of Aksoual and Bou Iguenouane in October 2013. On the NW face of Aksoual the northern cliffs of the ridge of Azrou n’Tamadot represent one of the largest cliff faces in the Atlas Mountains rising 1500 m inc. 2 km. A potential fourth moraine unit (not marked in Fig. 12) is
glaciation that has occurred in the Late Holocene may be detectable using exposure dating. If a niche glacier was present at this site in the have only existed under the topoclimatic controls, and Late Holocene, then it could influence of very strong local possibly debris cover. This is known to have been the case for the Pleistocene Late-gla- cial in the Marrakech High Atlas when equilibrium line altitudes of glaciers varied by > 1000 m (Hughes et al. 2020). Alternatively, these moraines may be Late Pleisto- cene in age since some cirque moraines elsewhere at the
glaciation that has occurred in the Late Holocene may be detectable using exposure dating. If a niche glacier was present at this site in the have only existed under the topoclimatic controls, and Late Holocene, then it could influence of very strong local possibly debris cover. This is known to have been the case for the Pleistocene Late-gla- cial in the Marrakech High Atlas when equilibrium line altitudes of glaciers varied by > 1000 m (Hughes et al. 2020). Alternatively, these moraines may be Late Pleisto- cene in age since some cirque moraines elsewhere at the
Fig. 10 Snow filled the entire hollow between moraine ridges below the Tazaghart Névé Permanent in April 2012 (photograph by George Hannah). The depth from the moraine crests to the base of the hollow is up to 30 m in places. The bottom photograph shows the same loca- tion in September 2019 (photograph by Philip Hughes) Fig.9 Geomorphological map of the Tazaghart Névé Permanent (site 1 in Fig. 2; stratigraphical unit 4 in Fig. 8) and clast data from the sediment ridges bounding this feature. The clast form analysis from
Fig. 10 Snow filled the entire hollow between moraine ridges below the Tazaghart Névé Permanent in April 2012 (photograph by George Hannah). The depth from the moraine crests to the base of the hollow is up to 30 m in places. The bottom photograph shows the same loca- tion in September 2019 (photograph by Philip Hughes) Fig.9 Geomorphological map of the Tazaghart Névé Permanent (site 1 in Fig. 2; stratigraphical unit 4 in Fig. 8) and clast data from the sediment ridges bounding this feature. The clast form analysis from
two sites on each ridge shows that clasts are prediminantly blocky, subrounded and with some clasts displaying striae. No soil develop- ment was apparent on the surface of either sediment ridge (from Han- nah et al. 2017)
two sites on each ridge shows that clasts are prediminantly blocky, subrounded and with some clasts displaying striae. No soil develop- ment was apparent on the surface of either sediment ridge (from Han- nah et al. 2017)
separated into morphostratigraphical units, unlike for the Aksoual area (see Fig. 12) because of the lack of geochronological control for this area Fig. 11 Glacial geomorphological map of the central Toubkal area. Not all moraines are shown, especially smaller features in the high- est cirques. The map is from Hughes et al. (2018) who focused on the Late Pleistocene history of the region. The moraines have not been
separated into morphostratigraphical units, unlike for the Aksoual area (see Fig. 12) because of the lack of geochronological control for this area Fig. 11 Glacial geomorphological map of the central Toubkal area. Not all moraines are shown, especially smaller features in the high- est cirques. The map is from Hughes et al. (2018) who focused on the Late Pleistocene history of the region. The moraines have not been
Fig.12 Glacial geomorphological map of the Aksoual area, c. 5-10 km NE of Toubkal. The moraines were dated using cosmogenic exposure dating (!°Be and *°Cl) and subdivided into morphostrati- graphical units by Hughes et al (2018). Unit 3 moraines were thought to be Pleistocene Late-glacial in age based on correlations with some dated moraines (e.g. sites P and Q in the Irhzer n’Likemt). However, some Unit 3 moraines may be younger and there is evidence that younger moraines and pronival ramparts are present inside of these unit 3 moraines, close to cirque backwalls and associated with late- lying snow (see Table 2 for locations). From Hughes et al. (2018)
Fig.12 Glacial geomorphological map of the Aksoual area, c. 5-10 km NE of Toubkal. The moraines were dated using cosmogenic exposure dating (!°Be and *°Cl) and subdivided into morphostrati- graphical units by Hughes et al (2018). Unit 3 moraines were thought to be Pleistocene Late-glacial in age based on correlations with some dated moraines (e.g. sites P and Q in the Irhzer n’Likemt). However, some Unit 3 moraines may be younger and there is evidence that younger moraines and pronival ramparts are present inside of these unit 3 moraines, close to cirque backwalls and associated with late- lying snow (see Table 2 for locations). From Hughes et al. (2018)
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