Bollettino di Geofisica Teorica e Applicata
OGS Website
About the Journal
Contacts
To Authors
On-line Submission
Subscriptions
Forthcoming
On-line First
The Historical First Issue
Issues

2022 Vol. 63
1 / 2 / 3

2021 Vol. 62
1 / 2 / 3 / 4 / Suppl. 1 / Suppl. 2 / Suppl. 3

2020 Vol. 61
1 / 2 / 3 / 4 / Suppl. 1

2019 Vol. 60
1 / 2 / 3 / 4 / Suppl. 1 / Suppl. 2 / Suppl. 3

2018 Vol. 59
1 / 2 / 3 / 4 / Suppl. 1

2017 Vol. 58
1 / 2 / 3 / 4

2016 Vol. 57
1 / 2 / 3 / 4 / Suppl. 1

2015 Vol. 56
1 / 2 / 3 / 4

2014 Vol. 55
1 / 2 / 3 / 4

2013 Vol. 54
1 / 2 / 3 / 4 / Suppl. 1 / Suppl. 2

2012 Vol. 53
1 / 2 / 3 / 4

2011 Vol. 52
1 / 2 / 3 / 4 / Suppl. 1

2010 Vol. 51
1 / 2-3 / 4 / Suppl. 1

2009 Vol. 50
1 / 2 / 3 / 4

2008 Vol. 49
1 / 2 / 3-4 / Suppl. 1

2007 Vol. 48
1 / 2 / 3 / 4

2006 Vol. 47
1-2 / 3 / 4

2005 Vol. 46
1 / 2-3 / 4

2004 Vol. 45
1-2 / 3 / 4 / Suppl. 1 / Suppl. 2

2003 Vol. 44
1 / 2 / 3-4

2002 Vol. 43
1-2 / 3-4

2001 Vol. 42
1-2 / 3-4

2000 Vol. 41
1 / 2 / 3-4

1999 Vol. 40
1 / 2 / 3-4

1998 Vol. 39
1 / 2 / 3 / 4

1997 Vol. 38
1-2 / 3-4

1995 Vol. 37
145 / 146 / 147 / 148 / Suppl. 1

1994 Vol. 36
141-144 / Suppl. 1

1993 Vol. 35
137-138 / 139 / 140

1992 Vol. 34
133 / 134-135 / 136

1991 Vol. 33
129 / 130-131 / 132

 
 

Vol. 35, n.139, September 1993
pp. 383 - 393

Some aspects of sensitivity analysis in one dimensional magnetotelluric modelling

K.K. Roy and A.K. Singh

Abstract

Sensitivity analysis for a certain class of 1 D MT modelling is done to highlight a few points of principle. The analysis reveals that (1) skin depth at crossover point frequency in 1D MT response (explained in the text) roughly estimates the top of the second layer for a certain class of three layer earth models; (2) the MT signal can feel the presence of an inhomogeneity when it la beyond the skin depth level; (3) a linear relation exists between the depth and thickness of the middle layer for some three layered H and K type earth models for the same percentage anomaly; (4) sensitivity drastically falls when the resistivity contrast exceeds 100; (5) the relation between thickness of the middle layer for a three layered H type model and the frequency at which the apparent resistivity becomes minimum la also linear; (6) the relation between thickness of the second layer for both K and H type models and the percentage anomaly at minimum or maximum frequency (explained in the text) la nonlinear; (7) the ratio of the wavelength at the perturbation centroid frequency (explained in the text) and the target bed thickness varies within a few orders of magnitude; (8) sensitivity of MT response for resolving a resistive bed in between two conductive bed becomes low, and vanishes for a certain class of models; (9) one or two kilometers of conductive overburden significantly reduces the sensitivity of the MT response from well inside the upper mantle up to 300 km to 500 kin depth where the olivine structure of the mantle silicates changes to different phases of the spinel structures.

Download PDF complete



back to table of contents