Transcript Scaling laws of the size distribution of monogenetic volcanoes within

Scaling laws of the size distribution
of monogenetic volcanoes within
the Michoacan-Guanajuato
Volcanic Field (Mexico)
Michoacan-Guanajuato Volcanic
Field
• 1040 monogenetic volcanoes
– Mainly basaltic cinder cones
• Used size of m-volcano defined by basal diameter
– 1 or very few magma pulses
• Rivera and Cocos plate subduction
– Transmexican Volcanic Belt (TMVB)
– Largest intra continental volcanic arc
• Estimated morphometric parameters (height, diameter [base
and crater], and volume)
– Gathered information from topo maps and measurements in the field
Conclusions
• Similar power-law to Gutenberg-Richter
– Respect to size-distribution
• Log10[N(size>Wco)] = a – b log10[Wco]
– b: rate of occurrence between small/large volcanoes
– N: # volcanoes with diameter greater than Wco (1.33km)
• a = 2.98, b = 5.02, Wco > 1.33 km
• Self-organized criticality phenomenon
– Monogenetic fields distributed as fractal in size
• Formula can be applied to future volcanoes
– Assess hazard
– B-paramater directly related to monogenetic volcanic activity
– Size distribution does not occur randomly
Gutenberg-Richter Law
• The number of earthquakes of magnitude M is
proportional to 10-bM
• Look at the graph (all the earthquakes in 1995)
– red line gives the Gutenberg-Richter prediction with b = 1. The
value of b seems to vary from area to area, but worldwide it
seems to be around b=1.