brocher: Convert between material properties and seismic velocities.
In abarbour/hydrogeo: Tools for hydrogeology and poroelasticity

Description Usage Arguments Details Value Author(s) References See Also Examples

Uses the empirical relations from Brocher (2005) to convert material properties into seismic velocities, and the other way around. A function to convert density into porosity is also provided.

From.Vp(Vp, ...)

as.RockDensity(Vp, pos = seq_along(Vp), emp.fit = c("nafe_drake", "gardner",
  "christensen_mooney", "godfrey"), do.all = TRUE, all.average = do.all,
  Vp.units = NULL, verbose = TRUE)

dens_nafe_drake(Vp, null_val = NA)

## Default S3 method:
dens_nafe_drake(Vp, null_val = NA)

dens_gardner(Vp, null_val = NA)

## Default S3 method:
dens_gardner(Vp, null_val = NA)

dens_christensen_mooney(Vp, null_val = NA)

## Default S3 method:
dens_christensen_mooney(Vp, null_val = NA)

dens_godfrey(Vp, null_val = NA)

## Default S3 method:
dens_godfrey(Vp, null_val = NA)

as.Vs(Vp, pos = seq_along(Vp), emp.fit = c("brocher", "castagna",
  "brocher_mafic"), do.all = TRUE, all.average = do.all, Vp.units = NULL,
  verbose = TRUE)

vs_brocher(Vp, null_val = NA)

## Default S3 method:
vs_brocher(Vp, null_val = NA)

vs_castagna(Vp, null_val = NA)

## Default S3 method:
vs_castagna(Vp, null_val = NA)

vs_brocher_mafic(Vp, null_val = NA)

## Default S3 method:
vs_brocher_mafic(Vp, null_val = NA)

as.Vp(X, pos = seq_along(X), emp.fit = c("brocher", "brocher_ludwig"),
  do.all = FALSE, all.average = FALSE, Vp.units = NULL, verbose = TRUE)

vp_brocher(Vs, null_val = NA)

## Default S3 method:
vp_brocher(Vs, null_val = NA)

vp_brocher_ludwig(Dens.bulk, null_val = NA)

## Default S3 method:
vp_brocher_ludwig(Dens.bulk, null_val = NA)

vpvs_continuum(nu)

## Default S3 method:
vpvs_continuum(nu)

nu_continuum(Vp, Vs)

## Default S3 method:
nu_continuum(Vp, Vs)

as.PoissonsRatio(Vp, pos = seq_along(Vp), emp.fit = c("brocher",
  "brocher_ludwig"), do.all = FALSE, all.average = FALSE, Vp.units = NULL,
  verbose = TRUE)

nu_brocher(Vp, null_val = NA)

## Default S3 method:
nu_brocher(Vp, null_val = NA)

nu_brocher_ludwig(Vp, null_val = NA)

## Default S3 method:
nu_brocher_ludwig(Vp, null_val = NA)

as.Porosity(Dens.bulk, Dens.solid = 2.8, Dens.fluid = 1, non.neg = TRUE,
  dens.units = NULL, return.percent = FALSE, return.voidfrac = FALSE,
  verbose = TRUE)

`Vp`	numeric; the P-wave velocity of the rock in km/s
`...`	additional parameters
`pos`	numeric; vector of indices or distances for `Vp`
`emp.fit`	character; the empirical fit to use [overridden if `(do.all \| all.average)`]
`do.all`	logical; should all available epirical scalings be calculated?
`all.average`	logical; should, once all available epirical scalings are calculated, the collection of results be averaged?
`Vp.units`	character; the units of `Vp`
`verbose`	logical; should messages be printed?
`null_val`	the value to fill in place of conversions outside of the valid range (see Details)
`X`	numeric; An object to convert
`Vs`	numeric; the S-wave velocity of the rock in km/s
`Dens.bulk`	numeric; the density of the
`nu`	numeric; Poisson's ratio
`Dens.solid`	numeric; the density of the
`Dens.fluid`	numeric; the density of the
`non.neg`	logical; should
`dens.units`	character; the units of the `Dens.` args.
`return.percent`	logical; should
`return.voidfrac`	logical; should

The empirical relations are based on regression curves based on material type, and thus restricted to within specific ranges of the independent variable, for specific material; the valid ranges are:

Valid rock/lithology types	Function	Validity		Eqn
		Lower	Upper
V[p] to ρ conversions
(km/s to g/cm^3)
All except mafic crustal and CA-rich	`dens_nafe_drake`	1.5	8.0	1
Sedimentary	`dens_gardner`	1.5	6.1	2
Cyrstalline (except volcanic and monomineralic)	`dens_christensen_mooney`	5.5	7.5	3
Basalt, diabase, and gabbro	`dens_godfrey`	5.9	7.1	4

*ρ to V[p]* conversions**
(g/cm^3 to km/s)
(see `dens_nafe_drake`)	`vp_brocher_ludwig`	2.0	3.5	5

V[p] to V[s] conversions
(km/s to km/s)
All except CA-rich and mafic, gabbros,	`vs_brocher`	1.5	8.0	6
and serpentinites
Clay-rich sedimentary	`vs_castagna`	1.5	4.25	7
CA-rich (inc. dolomites and anorthosites),	`vs_brocher_mafic`	5.25	7.25	8
mafic, and gabbros

V[s] to V[p] conversions
(km/s to km/s)
(See `vs_brocher`)	`vp_brocher`	0.0	4.5	9

V[p] to ν conversions
(km/s to [dimensionless])
(See `vs_brocher`)	`nu_brocher`	1.5	8.5	11
(See `vs_brocher`)	`nu_brocher_ludwig`	1.5	8.5	12

The field Eqn gives the equation number from Brocher (2005).

The functions nu_continuum and vpvs_continuum return Poisson's ratio and the V[p]/V[s] ratio for a continuum representation; is missing arguments they default to a Poisson solid (ν=1/4 or V[p]/V[s] = √{3}).

The parameter null_val can be set to fill points where any conversion lies outside the given range.

A data.frame for the as. functions; numeric otherwise.

Andrew J. Barbour <andy.barbour@gmail.com>

Brocher, T. M. (2005). Empirical relations between elastic wavespeeds and density in the Earth's crust. Bulletin of the Seismological Society of America, 95 (6), 2081-2092.

kms, hydrogeo.p