Relationship between dynamics of modern glaciers of the Mt. Munkhkhairkhan (Mongolian Altai) and climate

Mt. Munkhkhairkhan is the most crucial region for understanding climate and glaciation changes in Mongolia. This study investigated the relationship between glacial area changes and the climate elements of Mt. Munkhkhairkhan in the Mongolian-Altai Mountains using a remote sensing approach, in-situ observations, the Mann–Kendall (MK) test, Innovative Trend Analysis Method (ITAM), Sen’s slope estimator test, and statistical analysis. The study results showed that for the last 30 years, the annual average air temperature of Mt. Munkhkhairkhan has been slightly increasing. Total annual precipitation (mainly snow) in the mountain area decreased from 1990 to 2000, but since 2000, a significant increase in precipitation levels has appeared. For the last 30 years, the glacial area has decreased by 32% to 11.7 km2. Multiple regression results showed a strong correlation between Temperature, Precipitation, and Glaciers (Multiple R = 0.69, R2 = 0.48). Ruther indicated that Temperature (t = −2.332, p = 0.036) and Precipitation (t = −3.212, p = 0.007) were significant predictors in the model. Air temperature and precipitation explained 48 percent of the change in the glacier area, and R = 0.69 is a strong correlation. The glaciers and snow area in the study area have changed due to climate warming and precipitation changes and are located in arid and semi-arid regions of Central Asia. This study of Mt. Munkhairkhan shows that climate change significantly impacts glaciers and snow

Using MT for understanding the formation of non-volcanic geothermal systems: case study from Tsenkher geothermal area in Mongolia

Understanding the geological setting of nonvolcanic geothermal systems is vital to explaining the formation of geothermal reservoirs and their observable surface manifestations. The magnetotelluric method, used to determine the subsurface electrical conductivity distribution, is a common tool in geothermal exploration. In this study, we present an integrated interpretation of an electrical conductivity subsurface model, together with geological analyses and geochemical probes from a nonvolcanic, intermediate-temperature geothermal system in Mongolia. We conducted magnetotelluric (MT) and telluric-magnetotelluric (TMT) measurements at the Tsenkher geothermal area in the Mongolian Khangai dome during the summers of 2019 and 2020. The 20km*20km large area is characterized by three major hot springs with water temperatures up to 87°C. From a total of 196 MT and TMT stations, we obtained a 3-D electrical conductivity model of the subsurface. To interpret the data, we used a high-order finite-element electromagnetic modelling code (GOFEM) with locally refined hexahedral meshes that allows including accurate topography while ensuring high numerical accuracy with a sufficiently fine discretization of the inversion domain. The best-fitting model provides essential insights into the subsurface structure of the Tsenkher geothermal area. The model is characterized by a strong vertical crustal conductor that appears south of the hot springs area and rises from depths of more than 10 km to the surface. We interpret this conductor as a remnant of past local volcanism and a zone of former magma ascent, indicating the potential source for the observed enhanced surface heat flow in the hot springs area around Tsenkher. Additionally, the model includes a prominent striking conductor beneath the hot springs at depths down to more than 3 km below the surface. The conductor is spatially aligned with a major fault that intersects the survey area, and is accompanied by several basaltic dyke intrusions. We interpret the fault-aligned conductor as the major area of deep fluid circulation and an accumulation zone for heated fluids. The interpretation agrees with theoretical concepts of topography-driven deep fluid circulation and local fault zones playing a major role in the transport of hot water from a reservoir to the surface. Inferred reservoir temperatures from geochemical fluid analyses are inagreement with interpretations of the maximum depth of fluid circulation inferred from the MT model. Our MT subsurface model serves to better understand the formation of the Tsenkher hot springs in particular and intermediate-temperature geothermal systems in genera

Integrated geoscientific exploration for geothermal energy utilization in the Mongolian Hangai

ISSN:1029-7006ISSN:1607-796

Historically unprecedented global glacier decline in the early 21st century

Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (similar to 42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (similar to 5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable.</p