I would like to thank Mrs. M.Uuganzaya for helping in mapping and Mr. Robin Blomdin of Stockholm University for advice on remote sensing and mapping. I am also grateful to reviewers for helpful suggestions and constructive comments. This study was supported by National University of Mongolia in a year for encouraging research.
1Glaciers in high mountains in Mongolia not only play a vital role in water resources in Central Asia, regionally, but also in ecological, social and economical developments of the regions, locally. Glaciers in high mountain ranges provide over 70% of fresh water resources in Mongolia (Davaa, 2010). Glaciers are an indicator of the climatic temporal variability, i.e., melting of the ice masses in the mountains records temperature fluctuations. Furthermore, the air temperature can be of significant importance in glacier mountain catchments because it can modulate or even control the water resources through altering the glacier mass balance (Liu et al., 2015). It has been known that glaciers, especially the small mountain glaciers in high latitudes and high altitudes are very sensitive to climate change (Kitov et al., 2015).
2There is still poor scientific information about the glaciers in Khuvsgul Mountain Range, compared with data on the Altai Mountain Range, World Glacier Inventory or in the database of the US National Snow and Ice Data Center. However, rapid retreats of the glaciers during the Little Ice Age, especially in recent decades under rising temperature were observed in Khuvsgul Mountain Range based on aerial photographs, satellite images, topographic maps, remote sensing images and in-situ observation data (Kitov et al., 2009, 2015; Kovalenko, 2011, 2014). To date, numerous glacial studies have been conducted in Altai Mountain Range (Lehmkuhl, 2012; Kamp et al., 2013; Ganiushkin et al., 2015; Blomdin et al., 2016), however, there is an absence of any such study in Khuvsgul Mountain Range (fig. 1) except for data on morphometric changes in area and volume of the palaeoglaciers (Krivonogov et al., 2005; Gillespie et al., 2008). In this study, therefore, glacial landforms in the Mt (Mountain). Munkh Saridag region are presented in a glacial geomorphological map in order to underpin palaeoglacial reconstructions in Khuvsgul Mountain Range.
Fig. 1 – Location of the study area in the Khuvsgul Mountain Range.
Fig. 1 – Localisation de l'aire d'étude dans la chaîne de montagnes de Khuvsgul.
Red box denotes the location of area presented in detail in Figure 2.
Le cadre rouge précise l'aire décrite dans la figure 2.
3The Khuvsgul Mountain Range is one of the only three mountain ranges, namely Altai, Khangai and Khuvsgul in Mongolia (fig. 1) where modern glaciers exist. Khuvsgul Mountain Range in northern Mongolia includes isolated massifs extending southwest-northeast (fig. 2). The Khuvsgul Mountain Range experienced glaciations twice (Tsegmid, 1969) centered in Mt. Munkh Saridag (Jigj, 1976). An ice field spanning the Sayan and Ulaan Taiga Mountain Ranges centered in the Khuvsgul Mountain Range during the Last Glacial Maximum (LGM), the last period in the Earth's climate history during the last glacial period when ice sheets were at their greatest extension (Clark et al., 2009), blocked the River Shishkhid and formed the palaeolake in Darkhad basin (Grosswald and Rudoy, 1996; Komatsu et al., 2009) bounded by Sayan Mountain Range in the north, Bayan Zurkh Mountain Range and Khoridol Saridag Mountain Range in the east, and Mt. Ulaan Taiga in the west (fig. 2). According to Krivonogov et al. (2005), the remains of end, medial and lateral moraines in the valleys of Rivers Tengis and Shishkhid, a major tributary of the River Yenisei (fig. 2), and intermontane basins reveal that large glaciers advanced to Sayan and Khuvsgul Mountain Ranges in the Late Pleistocene. The Late Pleistocene glaciers around Darkhad basin advanced twice at 17-19 ka and 35-53 ka when end moraines were deposited, equilibrium-line altitudes (ELAs) were at ~1600 m a.s.l and 2100-2400 m a.s.l, respectively (Gillespie et al., 2008). The modern glacier complex in Mt. Munkh Saridag has formed only during the last 4000-5000 years, and the trend of shrinkage of glaciers since the end of the Little Ice Age can be traced, especially in recent years (Kitov et al., 2015).
Fig. 2 – Topography of Khuvsgul Mountains including the study area framed by a box (Mt. Munkh Saridag is presented in Figures 5-6 in detail).
Fig. 2 – Topographie des montagnes de Khuvsgul, incluant l'aire de la montagne de Munkh Saridag présentée dans les figures 5 et 6 (cadre rouge).
4Scientists note the rapid melting of glaciers, decreasing in glacier areas, disappearing small glaciers due to global warming in the Altai Mountain Range (Davaa, 2010; Otgonbayar, 2011; Lehmkuhl, 2012; Kamp et al., 2013). It is therefore important to understand the continuous glacier retreating and/or melting of the ice masses and quantify the dynamics of the modern glaciers in Mt. Munkh Saridag, in order to predict future water availability due to further rising temperatures for nomadic cultures, livestock and agricultures. This study aims to present detailed data on palaeoglacier remnants and dynamics of modern glaciers in Mt. Munkh Saridag in Khuvsgul Mountain Range (fig. 3-6) based on interpretations of Landsat images, topographic maps and analyses of AGDEM (ASTER DEM–Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model) data.
Fig. 3 – The modern glacier of the main summit of the Mt. Munkh Saridag on south facing slope (from Kitov et al., 2015). This glacier is facing Lake Khuvsgul in this photo.
Fig. 3 – Le glacier actuel, sur la face Sud du principal sommet de la montagne de Munkh Saridag (d'après Kitov et al., 2015). Sur cette photo, le glacier fait face au lac Khuvsgul.
5The Khuvsgul Mountain Range, the southeastern tip of Eastern Sayan Mountain Range, is located in the northern Mongolia (fig. 1), and is surrounded by Sayan Mountain Range in the north, isolated mountain ranges in the basins of Rivers Selenge and Orkhon in the southeast, and Khangai Mountain Range in the south (fig. 2). Mt. Munkh Saridag is in the center of Khuvsgul Mountain Range and is elevated up to 3491 m a.s.l at the border between Mongolia and Russia (fig. 2).
6Western mountains of the Khuvsgul Mountain Range are steep and sharp, and dissected by cliffs. For example, Ikh Agaya Mountain Range (2400-2800 m a.s.l) consisting of steep slopes, sharp peaks and taluses, extends from the Eastern Sayan Mountain Range in the north to Dood Taiga Mountain Range in the south and crosses River Shishkhid along the west of River Tengis in the northwest of Darkhad Basin (fig. 2). However, the northeastern and eastern mountains of the Khuvsgul Mountain Range are characterized by gentle slopes and domed peaks. Bedrock is largely schist and lesser granites in the Mt. Ulaan Taiga, but the Khoridol Saridag Mountain Range (3000 m a.s.l) is carbonate. Basalt flows are present in the valley of River Shishkhid (Academy of Sciences of Mongolia and Academy of Sciences of USSR, 1990). Generally, the western and eastern mountains in Khuvsgul Mountain Range are underlain by carbonate and volcanic rocks, respectively.
7Khuvsgul Mountain Range, located in the central part of Eurasia, serves as a watershed including large lakes and rivers of the Arctic Ocean basin, and is characterized by cool summers and extremely cold winters due to large annual temperature amplitude. According to data from the Khatgal meteorological station, average annual air temperature is -1.9°C with annual air temperature amplitude of 70°-80°C and daily air temperature amplitude of 20°-25°C. Average annual precipitation is 400-500 mm in the high mountains with a maximum in July. Density of rivers is high and most of rivers drain to River Shishkhid in the southwest, Lake Khuvsgul in the south and Rivers Eg and Selenge in the southeast (fig. 1). There are tectonically originated fresh water lakes. For example, Lake Khuvsgul is the deepest one. Around it permafrost and swamps are widely developed (Orkhonselenge et al., 2014).
8In the Khuvsgul Mountain Range, there are abundant palaeoglacier remains such as post-glaciers pediments, wide glacial depressions and large glacial lakes between Khoridol Saridag Mountain Range, Bayan Mountain Range, Ulaan Taiga Mountain Range, basin of River Shishkhid and the head of River Uur (fig. 2). Mt. Munkh Saridag, the northeastern end of Khuvsgul Mountain Range has steep slopes with cliffs and a number of palaeoglacier remains including cirques, U-shape valleys and moraines (Tsegmid, 1969; Jigj, 1975; Munkhuu, 1992). The central part of the Mt. Munkh Saridag massif is represented by alpino-type ridged watersheds, separated by numerous cirques, often with lakes in their bottoms (Kitov et al., 2015).
9In this study, Landsat satellite images (07/23/1986, 08/06/2000, 07/18/2007), AGDEM 30 m, 1:100 000 topographical maps (1970) and Google Earth are used for reconstructing palaeoglacier remains and determining dynamics of the modern glaciers of Mt. Munkh Saridag. Because glacial erosional and depositional landforms are key to palaeoglaciological studies, palaeoglacier remains of Mt. Munkh Saridag were reconstructed with visual interpretation of remotely sensed data following a pre-defined set of criteria (Heyman et al., 2008; Morén et al., 2011; Fu et al., 2012; Stroeven et al., 2013; Blomdin et al., 2016).
10A combination of Landsat 5TM imagery (30 m resolution) and AGDEM imagery (30 m resolution) was used as the primary data source for compiling on-screen digitizing of landforms (07/23/1986, 08/06/2000, 07/18/2007). For the satellite images with a high percentage of cloud cover and in areas with complex landform assemblages, Google Earth’s 3D viewing capability was used in order to delineate the glacial landforms. In the delineation, multiple RGB band combinations of “true” (RGB: 7, 4, 2) and “false” (RGB: 4, 3, 2) colour composites of Landsat 5 TM imagery were used. A semi-transparent layer of the satellite imagery was draped over the Aster GDEM data in an ESRI ArcGIS 10.1 environment to aid landform interpretation in complex topography (Glasser and Jansson, 2008). The extent and distribution of the modern glaciers were presented (fig. 3-4), and palaeoglaciers were mapped from the glacial landforms including terminal, medial and marginal moraines, glacial cirques and glacial U‑shaped valleys in the aerial photographs (fig. 5A). Marginal, medial and terminal moraines are displayed in red, light green and dark green, while glacial valleys and glacial cirques are shown in blue and yellow, respectively (fig. 5C). Conventional colours are used for other background information such as lakes, rivers and borders (fig. 1, fig. 2, fig. 5B-C). Normalized difference snow indexes (NDSI) are calculated for Mt. Munkh Saridag using a formula (NDSI = (GREEN‑SWIR1) / (GREEN+SWIR1)), to enhance the largest contrast between ice and snow (Munkhtuya, 2004). From the Aster GDEM data, hill shade models to simulate solar shading were computed (fig. 5E) and slope models to display slope steepness (fig. 5D). To best enhance the topographic signature of glaciated terrains, these models were set to grey scale colour ramps, with 50% transparency and draped over the original Aster GDEM data. The equilibrium-line altitude (ELA) estimation was based on the following steps: (1) contour lines were created with 10 intervals from the Aster GDEM elevation model map, (2) boundaries of glaciers in each selected year were overlapped with the contour lines, and (3) elevations of the highest and lowest parts for distribution of the glacier lines were calculated each year.
Fig. 4 – Surface area of the modern glaciers (m²) for each aspect in Mt. Munkh Saridag (fig. 3).
Fig. 4 – Surface couverte par les glaciers actuels (m²), pour chaque exposition des versants de la montagne de Munkh Saridag (fig. 3).
Fig. 5 – The Mt. Munkh Saridag Massif in the Khuvsgul Mountain Range.
Fig. 5 – Le massif du Munkh Saridag dans la chaîne de montagnes de Khuvsgul.
A. False colour Landsat 5TM image. B. Topography of Mt. Munkh saridag; C. Glacial landforms in mt. Munkh saridag with a grey-scale aster gdem: 1. Border; 2. Lake; 3. River; 4. Glacier; 5. Glacial valley; 6. Glacial cirque; 7. End moraine; 8. Medial moraine; 9. Marginal moraine. White numbers indicate examples of representative (1) Glacial u-shaped valley; (2) Glacial cirques; (3) End moraines; (4) Medial moraines; (5) Marginal moraines. D. Coloured aster gdem draped by a semi-transparent grey-scale slope model. E. Coloured aster gdem draped by a semi-transparent grey-scale hill shade model with the maximum paleoglacier reconstruction from the landform record (fig. 5C): 1. Border; 2. Glacier; 3. Maximum glaciation.
A. Image Landsat 5TM fausses couleurs. B. Topographie de la montagne de munkh saridag. C. Formes glaciaires dans la montagne de munkh saridag, superposées à un modèle d'élévation aster en niveaux de gris : 1. Frontière ; 2. Lac ; 3. Rivière ; 4. Glacier ; 5. Vallée glaciaire ; 6. Cirque glaciaire ; 7. Moraine terminale ; 8. Moraine médiane ; 9. Moraine frontale. Les chiffres en blanc localisent des exemples représentatifs de (1) vallées en auge ; (2) glaciers de cirque ; (3) moraines terminales ; (4) moraines médianes ; (5) moraines marginales. D. Modèle de pentes en niveaux de gris superposé par transparence à un modèle d'élévation aster. E. Modèle d'ombrage en niveaux de gris superposé par transparence à un modèle d'élévation aster, avec la reconstruction du paléoglacier à son maximum, selon les données de terrain (fig. 5C) : 1. Frontière ; 2. Glacier ; 3. Maximum glaciaire.
12Glacial landforms in Khuvsgul Mountain Range are compiled on a glacial geomorphological map as palaeoglacier remains (fig. 5A, C, E). The Khuvsgul Mountain Range has experienced glaciations several times in the Quaternary Period (Tsegmid, 1969; Jigj, 1976; Grosswald and Rudoy, 1996; Krivonogov et al., 2005; Gillespie et al., 2008). Mt. Munkh Saridag, the northeastern end of the Khuvsgul Mountain Range and/or the southeastern tip of Eastern Sayan Mountains (fig. 2) preserves abundant palaeoglacial landforms such as moraines on north and south aspects (fig. 5A, C, E) and U-shape valleys (fig. 6).
Fig. 6 – Glacial valleys in the Mt. Munkh Saridag.
Fig. 6 – Vallées glaciaires dans la montagne de Munkh Saridag.
A. Colored Aster GDEM draped by a semi-transparent gray-scale slope model with black lines showing the cross sections of U-shaped valleys. B. Location of cross-section profiles along the U-shaped valleys. C. Colored lines showing cross-section profiles of A, B, C, D and E. These profiles show shallow U-shaped glacial imprints in their cross-valley section.
A. Modèle de pentes en niveaux de gris superposé par transparence à un modèle d'élévation Aster (en couleur), les droites noires indiquant les coupes réalisées dans les vallées en auge. B. Localisation des coupes le long de la vallée. C. Les coupes A, B, C, D et E. Les coupes montrent une empreinte glaciaire en U peu profonde.
13Modern glaciers in Khuvsgul Mountain Range centered in Mt. Munkh Saridag (fig. 3) are observed as ice caps and hanging glaciers (fig. 5A) and are rapidly retreating in response to a warming climate. Recent studies (Kadota and Davaa, 2004; Lehmkuhl, 2012; Kamp et al., 2013; Kitov et al., 2015; Ganiushkin et al., 2015; Blomdin et al., 2016) have proven that many glaciers in Mongolia have been melting rapidly during observations of modern glacier. For example, in Mongolian Altai, Krumwiede et al. (2014) indicated that there has been a decrease in glacier area of ~30% (12 km²) and an increase in ELA by ~22 m between 1990 and 2006 in Mt. Munkh Khairkhan and glacier extents decreased by 4.2% (9 km²) between 1989 and 2009 in Mt. Tavan Bogd. Such rapid retreats are consistent with decreases in glacier areas in mountain ranges throughout the world that have been caused by global climate change (WGMS, 2008).
14In Mt. Munkh Saridag, modern glaciers consist of ice caps on top of mountain with a few occupying large cirques located at 3000 m a.s.l (fig. 2, fig. 5A, C). Moraines of modern glaciers are at 2705 m a.s.l and there is a mass wasting surface of 270 m wide and 500 m long until a small lake (fig. 5A-C). Areas of modern glaciers in Mt. Munkh Saridag are estimated to have been 900 m² in 1970, 851 m2 in 1986, 547 m² in 2000 and 384 m² in 2007 (fig. 4) and have decreased by 42.6% between 1970 and 2007. ELAs of the glacier exist at 2892 m and 3150 m a.s.l on north and south aspects, respectively, in 1970, whereas they lie at 2939 m and 3230 m a.s.l on north and south aspects, respectively, in 2007, i.e., the ELAs of the modern glaciers have risen by 47 m and 80 m on north and south aspects, respectively, between 1970 and 2007. According to Kitov et al. (2015), a comparison with earlier data revealed that the lower boundary of the modern glacier in 2006 was 132 m higher than in 1906, 38 m higher than in 1962, and 86 m higher than in 1982 for Mt. Munkh Saridag. Osipov et al. (2013) showed that over the past 160 years, the glacier area of Eastern Sayan Mountains decreased by 49%, and the glacier terminus retreated by 124 m in height, and showed that there is a single small glacier (0.12 km²) on the Mongolian side of Munkh Saridag in Sayan Mountain Range, north of Lake Khuvsgul. On the whole, there is a correlation with climate warming, as the firn portion of the glacier (granular snow, especially on the upper part of a glacier, where it has not yet been compressed into ice) is gradually reducing in its size, and the area of the modern glacier has decreased from 0.68 to 0.34 km² at Mt. Munkh Saridag since the end of the Little Ice Age, especially in recent years (Kitov et al., 2015). Although glacier area in Mt. Munkh Saridag in our estimation, is quite larger than that in the estimation by Osipov et al. (2013), it is similar to the estimation by Kitov et al. (2015).
15Modern glaciers in Mt. Munkh Saridag (fig. 3) are typically found (or 71.1% of total glacier area) on north facing slopes in 1970, but 4.1% of glaciers on southwest and west facing slopes in 1970 had completely disappeared by 2007 (fig. 4, 5C-E). The glaciers on the north, northeast and northwest aspects occupy the maximum areas in the years mentioned above (fig. 4). This demonstrates the retreat rate is higher on the southwest, west, northeast and east facing slopes, than on slopes with other aspects (fig. 4).
16On the map, glacial landforms were identified as end, medial and marginal moraines, glacial cirques and glacial valleys. Descriptions for the glacial landforms of Mt. Munkh Saridag in Khuvsgul Mountain Range are mainly based on the landform descriptions on the Tibetan Plateau, and in the Altai and Sayan Mountain Ranges in Central Asia (Heyman et al., 2008; Morén et al., 2011; Fu et al., 2012; Stroeven et al., 2013; Blomdin et al., 2016).
17Glacial valleys can develop in a single glacial cycle (Harbor et al., 1988), but typically develop over several glacial cycles and therefore signify locations that have been glaciated multiple times in the past (Li et al., 2005). Glaciated valleys have very steep sides and a wide, flat bottom resulting from a pattern of glacial erosion (Harbor, 1992; Li et al., 2005). Glacial valleys are large-scale landforms forming distinctive U‑shaped cross-sections (Li et al., 2005). Glacial troughs (U-shaped valleys with more gentle relief; see Heyman et al., 2008) are included in the glacial valleys (Blomdin et al., 2016). In Mt. Munkh Saridag, glacial valleys have been primarily identified based on the Aster GDEM slope model and Google Earth (fig. 5A, C). The appearance of the U‑shaped glacial valleys on the north and south aspects of Mt. Munkh Saridag (fig. 7) in the Aster GDEM slope model (fig. 6) shows complete glacial valleys differing from V-shaped valleys.
Fig. 7 – Glacial U-shaped valley in the Mt. Munkh Saridag.
Fig. 7 – Vallée en U dans la montagne de Munkh Saridag.
18Glacial cirques are formed in bowl-shaped depressions on mountain sides (Benn and Evans, 1998; Barr and Spagnolo, 2015). Although Heyman et al. (2008), and Blomdin et al. (2016) included the cirques in the category of glacial valleys, they have been identified in individual class in this study. Snow may be situated on the leeward slope of a mountain, where it is sheltered from wind, and rock-fall from above slopes also plays an important role in sheltering the snow and ice from sunlight (Lewis, 1960). In Mt. Munkh Saridag, glacial cirques are identified in Landsat imagery and the Aster GDEM (fig. 5A, C).
19End or terminal moraines are ridges of unconsolidated debris deposited at the snout or end of the glacier. They usually reflect the shape of the glacier’s terminus (Benn and Evans, 2010). The end moraines mark the maximum advance of the glacier. In Mt. Munkh Saridag, clearly exposed terminal moraines are most easily identified in Landsat imagery and Aster GDEM (fig. 5A, C). There are large terminal moraines (fig. 8) at 2380 m a.s.l, which mark palaeoglaciers advanced far away and small lakes formed by damming with the moraines (fig. 5A, C).
Fig. 8 – End moraines on southern aspect of the Mt. Munkh Saridag.
Fig. 8 – Moraines terminales sur la face Sud de la montagne de Munkh Saridag.
20A medial moraine is a ridge of moraine that runs down the center of a valley floor (Benn and Evans, 1998). Medial moraines form when two glaciers meet and the debris on the edges of the adjacent valley sides join. As the glacier melts or retreats, the debris is deposited and a ridge down the middle of the valley floor is created. Medial moraine ranges with several metres. At Mt. Munkh Saridag, medial moraines are identified at a junction of two valleys in Landsat imagery and Aster GDEM (fig. 5A, C).
21Marginal moraines are parallel ridges of unconsolidated debris carried along the glacial margin and deposited along the sides of a glacier. Because marginal moraines do not experience the postglacial erosion of the valley floor, they are usually preserved as high ridges (Benn and Evans, 1998). Furthermore, landforms formed by the deposition of glaciogenic sediments at the margins of active glacier snouts are described as marginal moraines (Benn and Evans, 2010). Multiple marginal moraines may develop as the glacier advances and retreats. Then, this subtype of moraines is identified from clearly exposed moraines with no vegetation cover in Landsat imagery (fig. 5A, C) and the Aster GDEM hill shade model (fig. 5E). The marginal moraines vary morphologically from single ridge to larger sediment complexes (Barr and Clark, 2012). Linear and curved forms of morphological features in the marginal moraines are observed in Mt. Munkh Saridag (fig. 5A, C).
22For spatial reconstruction of palaeoglacier extents in the Mt. Munkh Saridag, the aerial extent of glaciation (fig. 5E) based on the distribution of glacial landforms described above (see Section 4.1) is estimated. A maximum glacier extent (fig. 5E) was delineated in the GIS environment using the margins of glacial valleys and different types of the moraines. This method enables a straightforward delineation of the maximum glacier extent in formerly glaciated mountain regions using glacial landforms (Blomdin et al., 2016). This reconstruction based on remote sensing represents that this palaeoglaciological footprint yields a useful estimate of palaeoglacier coverage based on the distribution of glacial landforms and allows for a comparison with the modern glacier extent (Okishev, 2006; Blomdin et al., 2016). Consistency and accuracy of the glacial geomorphological mapping have been strengthened by previous mapping procedures (Heyman et al., 2008; Morén et al., 2011; Fu et al., 2012; Stroeven et al., 2013; Blomdin et al., 2016). In Mt. Munkh Saridag, the reconstructed palaeoglacier extent (fig. 5E) is compared with the modern glacier areas calculated from the Randolph Glacier Inventory (RGI) V 3.2 (Pfeffer et al., 2014) and the maximum glacier area is reconstructed to cover about 186 km² for the study area. Results from this study provide an expectation of that palaeoglaciers near 51°‑52°N in northern Mongolia may have retreated with faster rate for this individual Mt. Munkh Saridag. This prediction could be clearly reflected on temporal information from the age of past ice expansions/advances in Mongolia in further study.
23Extent of the palaeoglaciers in Khuvsgul Mountains in northern Mongolia has been spatially reconstructed as 186 km² with outer limits of glacial valleys, glacial cirques, terminal moraines, medial moraines and marginal moraines. With the reconstruction from these glacial landforms, large terminal moraines formed by several glacial advances are mainly located at the end of outlets of U‑shapes valleys or/and outside of the main mountain massifs (fig. 5A, C). By determining the maximum glaciers, as indicated by the distributions of preserved glacial landforms, the spatial analyses of glacial valleys and terminal moraines indicate that these mountain ranges were covered by large ice field glaciations in the past (fig. 5E), with centers of ice caps on the mountain peaks (fig. 5C). The past glacier coverage may be revealed to detailed field investigations and temporal analyses using various dating techniques in further studies. The spatial analysis of the modern glaciers in the Khuvsgul Mountain Range shows that glacier areas in Mt. Munkh Saridag have decreased by 42.6% between 1970 and 2007. In Mt. Munkh Saridag, the ELAs of the modern glaciers have risen by 47 m and 80 m on north and south aspects, respectively, between 1970 and 2007 (see Section 4). These changes of the modern glaciers (fig. 3-4) may be related to topographical elements of elevations and aspects, as well as durations of solar radiation and vulnerability to the solar insolation. This study demonstrates the usefulness of spatial analyses for reconstructing palaeoglaciology, which would be detailed with dates in further work.