Geomorphometric imprints of flank collapses on volcanic edifices: Implications from the case of Mount St. Helens
Küçük Resim Yok
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Analyzing the geomorphometric traces of volcanic eruptions by comparing pre- and post-eruption maps and images of volcanic edifices can quantitatively indicate drastic changes in topography enlightening the effects of volcanic flank collapses. Volcanic edifices are inherently prone to experience flank collapses and related large landslides at some point of their evolution, which significantly change the volcanic landscape and totally destroy everything in their paths. If the flank collapses occurred on volcanic edifices in islands, they are also adequate to cause tsunamis with larger devastating effects. Thus, recognizing the imprints of flank collapses and their effects on volcanic edifices has critical importance. Comparison of pre- and post-eruption elevation, slope, aspect, and hypsometry analyses of the regular cone-shaped pre-eruption volcanic edifice as in the case of May 18, 1980 eruption of Mount St. Helens in Washington provides an excellent opportunity to understand the influence of such a rapid catastrophic event on landscape evolution. The volcanic flank collapse during the eruption particularly affected the upper 1500 m. The collapsed part increased the percentage of region between 1500 and 2150 m, particularly accumulated around similar to 1950 m, and created a plateau morphology because of landsliding and debris avalanche. The maximum and average maximum slope values of the edifice significantly increased in the upper part of this altitude due to flank collapse-related scar development. Post-eruption redistributions of slope values and aspect directions have also changed obviously, and represent the signatures of an amphitheater (horseshoe/C-) shaped scarp and plateau morphology developments particularly for the highest (40 degrees <) and lowest (0-10 degrees) slope ranges, respectively. On the other hand, the comparison of pre- and post-eruption hypsometries of the volcanic edifice represents an increase against the decreased relief of the volcanic edifice as a result of the flank collapse and landsliding, which created a large plateau on the northern sector, affected the elevation-area relation of the volcanic edifice in a different way. The results represent how such a destructive event can be a rejuvenating process on the topography as in the case of Mount St. Helens by increasing slope and hypsometry.
Açıklama
Anahtar Kelimeler
Volcanic geomorphology, Volcanic flank collapse, Landslide, Debris avalanche, Hypsometry, Stratovolcano, Volcanic eruption, Washington
Kaynak
Environmental Earth Sciences
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
81
Sayı
4
