The 20-year average retreat rates (1990 2010 period) for 19 slumps ranged from 7.2 to 26.7 m yr− 1, with the largest slumps having higher retreat rates.
The results indicate that glacial fragmentation, higher retreat of small glaciers, and climate change are all influencing the sustainability of Himalayan glaciers.
At the regional scale, the 20-yr headwall retreat rates are mainly related to slope aspect, with south- and west-facing slopes exhibiting higher retreat rates, and large slumps appear to be generating feedbacks that allow them to maintain growth rates well above those of smaller slumps.
On 6 July 1948, Jinnah returned to Quetta, but at the advice of doctors, soon journeyed to an even higher retreat at Ziarat.
TOO MUCH TRADING Buying and selling too often tends to hurt returns, both because of the commissions you usually pay and because of investors' tendency to pile in when prices are high and retreat when things look grim.
Table 3 Overall crop yield reductions on subsided agricultural fields in Illinois Mining type Corn yield reduction a Year 1 Year 2 Year 3 Mean Longwall 7.4 4.2 2.4 4.7 High extraction retreat 2.4 2.2 0.9 1.8 aWeighted average reduction in yield.
These include high extraction retreat, where the roof supporting pillars are systematically removed, and longwall mining, which employs a machine that mines a continuous strip of coal, thus leaving no roof supports.
The combination of the two approaches resulted in an estimated overall weighted average yield reduction for longwall and high extraction retreat mining of 4.7 and 1.8 %, respectively, for all sites over the research period (Table 3).
In the early 1980s coal companies planned to take advantage of those reserves and of the efficiency of longwall mining, and a related form of mining known as High Extraction Retreat where the roof supporting coal pillars are removed to increase production ratios.
With 20-odd fresh-faced students, three of them girls, living in dorms on site, it reminded me of a high school retreat.
