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This article investigates Haast's claim that in March 1862 he independently reached the same controversial conclusion as Ramsay, that lake basins in previously glaciated regions were formed by ancient glaciers. Both men's views fuelled a passionate debate in British scientific societies. However, science historians largely ignore Haast's contribution or imply he knew about Ramsay's 'theory' before coming to a conclusion about Southern Alps lakes. To assess whether Haast independently reached that conclusion in March 1862, field records, correspondence, reports, newspaper articles, and scientific publications are examined. Of significance are communications with geologists Hochstetter, Hector, and Ramsay, botanist Hooker, and physicist Tyndall. Consideration of what Haast observed in March 1862 is also critical. However, Haast's 1862 conclusion differs from Ramsay's. While Ramsay was convinced ancient glaciers scooped out rock basins, resulting in deep lakes, Haast believed ancient retreating glaciers left moraines that dammed valleys, resulting in shallow lakes. Regardless of their differences, after Haast read Ramsay's paper in 1864, he applied Ramsay's 'theory' to New Zealand's alpine lakes and proposed an excavation process. The essence of both Ramsay's and Haast's conclusions has been confirmed by research in formerly glaciated regions worldwide. However, Haast's contribution to glaciology is overlooked or underemphasized, and warrants being more widely acknowledged. [ABSTRACT FROM AUTHOR]

As an integral part of the Asian water tower, the spatiotemporal characteristics of Himalayan glaciers are closely linked to climate and the environment. Using Landsat TM/ETM+/OLI image data, the distributions of and changes in glacial areas in the middle Himalayas from 1990 to 2020 were extracted and analysed through the ratio threshold method and manual visual interpretation. The findings revealed a retreat of glaciers over the past 30 years, with the glacial area decreasing from 8584.75 km2 in 1990 to 7210.79 km2 in 2020, indicating a reduction of 1373.97 km2 (16.00%) and an average annual retreat rate of 0.53%. Debris-covered glaciers and debris-free glaciers show similar proportions in the study area, but the former exhibit a significantly lower annual retreat rate (−0.30%) than the latter (−0.78%), suggesting that moraine may impede glacier retreat. Glacial morphology encompasses valley glaciers, hanging glaciers, cirque glaciers, cirque valley glaciers, and flat-topped glaciers. Among these glaciers, valley glaciers constitute the primary glacier type in the study area, accounting for approximately 50% of the total area, whereas flat-top glaciers are the least common. Moraines associated with valley glaciers are relatively developed; debris-covered glaciers represent 75.74% of this glacier type, whereas flat-topped glaciers are entirely debris-free. [ABSTRACT FROM AUTHOR]