SciELO - Scientific Electronic Library Online

 
vol.38 issue2LATE HOLOCENE PALEOXYGENATION AND PALEOPRODRUCTIVITY OF THE PANAMA GULFMULTISCALE ANALYSIS OF CYCLICITIES IN WELL LOGS FROM THE WAVELET TRANSFORM, APPLIED TO CAMPO COLORADO author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Article

Indicators

Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google

Share


Boletin de Geología

Print version ISSN 0120-0283

Abstract

VELASQUEZ-ROCHA, Laura Vanessa  and  SANCHEZ-AGUILAR, John Jairo. PHYSICAL ANALYSIS OF THE SPATIAL DISTRIBUTION OF HUMMOCKS FROM THE DEBRIS AVALANCHE LOCATED IN THE AREA OF NEREIDAS, WEST FLANK OF NEVADO DEL RUIZ VOLCANO. bol.geol. [online]. 2016, vol.38, n.2, pp.93-100. ISSN 0120-0283.  http://dx.doi.org/10.18273/revbol.v38n2-2016006.

Debris avalanches represent great hazard for communities neighboring volcanoes. Rapid modification of landforms during these processes makes it difficult understanding the dynamics of the slides, estimating their magnitudes and assesing their damage. The analysis of preserved hummocks along the path of avalanches, however, becomes a tool to interpret the physical characteristics of debris avalanches. In this work a group of 281 hummocks emplaced west of Nevado del Ruiz Volcano, in the Nereidas area, is studied. Both, the spatial distribution and dimensions of the emplacement are calculated using GPSdetermined positions of individual hummocks as well as orthoimages and high-resolution topography. A negative correlation is found between the base area of hummocks and their distances to two probable sources. The most likely source area for the avalanche and a NW general direction of transport with some topography controls were also determined. The mobility of the avalanche (L/H) and its reciprocal the friction coefficient (H/L) were determined as 6.8 and 0.15, respectively. Analysis of the information and the results lead to the conclusion that the deposit corresponds to a minor debris avalanche younger than 40000 years, during which materials collapsed from a height of 2.6 km and reached a horizontal distance of 17.8 km (6.8 times greater than the collapse height), covering a total area of 47.7 km2 and transporting an estimated total volume equal to 5.05x10-3 km3, which is considered an underestimate.

Keywords : debris avalanche; volcanic ediffice collapse; hummocks; transport direction; mobility; friction.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )