国际滑坡领域著名科学家、英国谢菲尔德大学副校长Dave Petley教授,2018年12月14日,在其“The Landslide Blog(滑坡博客)”中,以“The Nyixoi Chongco
rock avalanche in Tibet”为题目,撰文高度评价程谦恭团队,近期关于青藏高原高速远程滑坡的研究成果,全文如下:
“The Nyixoi Chongco rock
avalanche in Tibet
In a new paper in the journal Landslides, Wang et al. (2018) describe
the Nyixoi Chongco rock avalanche in Tibet. I have not seen this spectacular rock avalanche in the literature before
this paper; it is an excellent addition to the inventory of such events. The dry, low vegetation environment of the
Tibetan Plateau has meant that the rock avalanche is beautifully preserved in
the landscape. Whilst the paper itself
is a little vague on the exact location, I have managed to track it down to
29.534, 90.263, a spot that has excellent Google Earth imagery:-
Google Earth
imagery of the the Nyixoi Chongco rock avalanche in Tibet
According to Wang et al. (2018), the Nyixoi Chongco rock avalanche
involved a mass of 28 million cubic metres descending a vertical distance of
885 metres, and traveling a total of 4.6 km horizontally, representing
exceptional mobility. The landslide
deposit is about 50 metres thick. The
authors do not give an estimated age for the rock avalanche, nor a definite
trigger mechanism, but the proximity to active faults makes them suspect that
an earthquake might have been involved. Wang et al. (2018) note that a nearby fault is thought to have generated
a magnitude 7.0 earthquake about 2,200 years BP; this would have induced
sufficiently intense shaking to have triggered a rock avalanche of this type.
The Nyixoi Chongco rock avalanche can be better appreciated in this
Google Earth oblique view:-
Google Earth perspective view of the Nyixoi Chongco rock avalanche in
Tibet
I have placed the marker at the crown of the landslide scar, which has
a scoop morphology. Below this is a very
clear transportation zone, stripped by the passage of the landslide. The deposit starts from the foot of the slope
and extends down the valley. Note the
clear hummocks in the landslide mass, which are very common for large rock
avalanches. Wang et al. (2018) note that
the landslide has many of the common characteristics of large rock avalanche
masses, including a very coarse (i.e. boulder-rich) carapace (the surface
layer), and a highly fragmented main landslide mass. The base of the landslide mass shows almost
no mixing with the valley deposits, and has sedimentary structures that suggest
that these deposits were unsaturated when the landslide was deposited. The authors suggest that the movement of the
landslide was not associated with any of the complex mechanisms sometimes
postulated for these huge rock avalanches, in this case involving simple shear
between the landslide mass and the valley floor.
It is interesting to note that this means that the landslide could have
high mobility without needing liquefaction or anything more exotic, a finding
that is important in the context of understanding other large events.
Reference
Wang, YF., Cheng, QG., Shi, AW. et al. 2018. Sedimentary deformation
structures in the Nyixoi Chongco rock avalanche: implications on rock avalanche
transport mechanisms. Landslides https://doi.org/10.1007/s10346-018-1117-7”
Dave Petley教授认为:“在这篇论文之前,我还没有在文献中看到过这种壮观的岩崩,这对这些事件目录的一个极好的补充(I have not seen
this spectacular rock avalanche in the literature before this paper; it is an
excellent addition to the inventory of such events.)”;“值得注意的是,这意味着滑坡可以具有很高的流动性,而不需要液化或任何更奇异的东西,这一发现对于理解其他重大事件是很重要的(It is interesting
to note that this means that the landslide could have high mobility without
needing liquefaction or anything more exotic, a finding that is important in
the context of understanding other large events.)”。
Dave Petley撰写的“The Landslide Blog(滑坡博客)”,以评价和分析世界各地重大滑坡事件和著名研究成果而闻名,在全球“地球与空间科学领域(Voice of the Earth
and Space Science Community)”享有盛名。
论文链接:Sedimentary
deformation structures in the Nyixoi Chongco rock avalanche: implications on
rock avalanche transport mechanisms
SpringerLink https://link.springer.com/article/10.1007/s10346-018-1117-7
博客链接:The Nyixoi Chongco
rock avalanche in Tibet - The Landslide Blog - AGU Blogosphere
https://blogs.agu.org/landslideblog/2018/12/14/nyixoi-chongco-rock-avalanche/?utm_source=AGU+Blogosphere+-+The+Landslide+Blog&utm_campaign=a2230e250d-RSS_EMAIL_CAMPAIGN_LANDSLIDE&utm_medium=email&utm_term=0_b2461e255e-a2230e250d-555512505