Slope

New models of eastern Tibetan hillsides show that steep slopes with “excess” rock last longer on average than their shallower counterparts.

“We’re not yet to the point where we can say when a specific hillslope will fail,” said Seulgi Moon, a geomorphologist at the University of California, Los Angeles, and a study coauthor, but the findings could help local scientists identify cliff faces to monitor for potential landslide risks. Their analyses focused on the idea of “excess” rock, the volume of rock that extends beyond that critical threshold angle, which changes among rock types and varies between 29° and 39° in their study region. explore the residence times, or “lifetimes,” of oversteepened slopes in the eastern margin of the Tibetan Plateau. The study combines 20-year records of landslides, long-term uplift rates, and models of erosion to estimate slopes’ lifetimes.

This month, I'm serializing my 2003 Harvard Law Review article, The Mechanisms of the Slippery Slope.] An intermediate position A might also be untenable if ...

{The Court might shift back to 0 instead—for instance, it might strike down a discriminatory school choice program and leave it to the legislature to choose whether to reenact it including the religious schools (move to B) or to abandon it altogether (stay at 0). But the Court might not do this; and even if it does, the parents who had been taking advantage of program A would strongly pressure the legislature to choose position B—which would at least preserve the school choice program that the parents had been using—instead of position 0. If a legislature exempts labor picketing from a residential picketing ban (A), then a court will likely strike down the ban altogether (B), because content-based speech restrictions are presumptively unconstitutional. A rule that doctors may only assist patients who have certain reasons for suicide may seem defensible in principle, and may seem practicable enough that even those who are skeptical of broader assisted suicide schemes would endorse it. But over the years, the Court extended the potential zone of free exercise protection to cover even idiosyncratic, seemingly not fully consistent beliefs, as well as beliefs that may not be central to people's religions, partly because the Justices concluded that secular courts cannot properly inquire into the religious beliefs' centrality and consistency. And once a law punishes the display of vaguely defined "pornography"—for instance, on the grounds that such displays constitute sexual harassment—it becomes likely that this law will be applied to "legitimate art" as well. The decisions that proposal A would require might also prove burdensome if they are seen as too arbitrary or as involving too much second-guessing of others' judgments.

The skier in the video below went for the unintentional ride of a lifetime when he fell on a groomed slope of Zillertal Arena, Austria.

I got lucky and managed to get away with just a few bruises. He claims to have slid 1100 meters (3608.924 ft.), and probably would have kept going if not for the safety netting that finally brought him a halt. Be very careful on steep, icy slopes and learn how to self arrest!

The critical shear stress is a vital reference indicator for soil erosion. Soil erosion will occur when soil slope suffers from a exceed shear stress, ...

In addition, the critical shear stress is negatively influenced by the particle diameter and positively influenced by the internal friction angle. Studies on the critical shear stress for soil erosion have focused on the direct measurement of critical shear stress. First, the flow rate of the valve should be calibrated by marking the valve position for a certain flow rate (0.4 L/s, 0.5 L/s and 0.6 L/s). Second, the soil material should be filled in the testing flume with the flat slope surface parallel to the flume surface. By comparison, theoretical values of the critical shear stress are calculated from Eq. ( 15), which are also given in Table 3. The indicator ε, which can be calculated using Eq. ( 16), was applied to certify the accuracy of the simple measurement. According to Eq. ( 17), the erosion rate ε can be calculated for different times t (Fig. 5). For each curve, the ε-values varied slightly with time, indicating that the slope was steady. In this way, the erodibility coefficient kd and the critical shear stress τc of the soil can be obtained based on linear regression 26. A bolted connection exists between the guiding flume and the testing flume, which allows the slope gradient to be adjusted by changing the height of the jack to rotate the testing flume. According to a series of scouring tests, a fitted line can be obtained, resulting in the kd and τc -values. Four different bed shear conditions for a sedimentary bed were characterized with no transport, weak transport, medium transport, and general transport, where the shear stress with general transport was defined as the critical shear stress 19. Finally, the influence of all parameters on the critical shear stress was analyzed: the porosity of the soil, the specific gravity of the soil and the slope gradient had less influence on the critical shear stress; the critical shear stress was negatively influenced by the particle diameter and positively influenced by the internal friction angle of the soil. In the field of soil erosion, the erosion rate, which introduces the excess shear stress equation (see Eq. 1), is an important evaluation indicator 1, 2.