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Anchor proxy record to an astronomical solution

Source: R/astro_anchor.R
astro_anchor.Rd

Anchor the extracted signal to an astronomical solution using a GUI. The astro_anchor function allows one to tie minima or maxima in the proxy record to minima or maxima in an astronomical solution. By tying the proxy record to an astronomical solution one will generate tie-points which can be used to generate a astrochronological age-model As minima or maxima in the proxy record are tied to minima or maxima in an astronomical solution it is important to provide input which has clearly definable minima and maxima. As such input should be of a "sinusoidal" nature otherwise the extract_astrosolution=TRUE and/or extract_proxy_signal=TRUE options need to be set to TRUE to create sinusoidal signals.

Astronomical solutions option are:

Usage

astro_anchor(
  astro_solution = NULL,
  proxy_signal = NULL,
  proxy_min_or_max = "max",
  clip_astrosolution = FALSE,
  astrosolution_min_or_max = "max",
  clip_high = NULL,
  clip_low = NULL,
  extract_astrosolution = FALSE,
  astro_period_up = 1.2,
  astro_period_down = 0.8,
  astro_period_cycle = NULL,
  extract_proxy_signal = FALSE,
  proxy_period_up = 1.2,
  proxy_period_down = 0.8,
  proxy_period_cycle = NULL,
  pts = 3,
  verbose = FALSE,
  time_dir = TRUE,
  genplot = FALSE
)

Arguments

astro_solution

Astronomical solution to which the proxy record is anchored (matrix or data frame with two columns: age (e.g. in kyr) in column 1, insolation/angle/value in column 2). Its maxima or minima (see astrosolution_min_or_max) are the candidate tie points. Required, no default (Default=NULL gives an error).

proxy_signal

Proxy record to be anchored (matrix or data frame with two columns: depth or time in column 1, proxy value in column 2). Its maxima or minima (see proxy_min_or_max) are tied one by one to the astronomical solution. For the best results the astronomical component should be extracted first, either beforehand (filtering/cycle extraction) or with extract_proxy_signal = TRUE. Required, no default (Default=NULL gives an error).

proxy_min_or_max

Tie the maxima or the minima of the proxy record (character): "max" or "min". Default="max".

clip_astrosolution

Clip the astronomical solution to the age range clip_low to clip_high before anchoring (logical, TRUE or FALSE). Default=FALSE.

astrosolution_min_or_max

Tie to the maxima or the minima of the astronomical solution (character): "max" or "min". Default="max".

clip_high

Upper age limit of the clipped astronomical solution, in the unit of its first column (numeric); only used when clip_astrosolution = TRUE. Default=NULL.

clip_low

Lower age limit of the clipped astronomical solution, in the unit of its first column (numeric); only used when clip_astrosolution = TRUE. Default=NULL.

extract_astrosolution

Extract one astronomical cycle from the astronomical solution before anchoring (logical, TRUE or FALSE): a wavelet transform (analyse_wavelet) is computed and the cycle astro_period_cycle is extracted with extract_signal_stable. Default=FALSE.

astro_period_up

Factor by which astro_period_cycle is multiplied to give the upper (longest) period of the band extracted from the astronomical solution (numeric, > 1). Default=1.2.

astro_period_down

Factor by which astro_period_cycle is multiplied to give the lower (shortest) period of the band extracted from the astronomical solution (numeric, between 0 and 1). Default=0.8.

astro_period_cycle

Period of the astronomical cycle to extract from the astronomical solution, in the unit of its first column (e.g. kyr) (numeric, > 0); required when extract_astrosolution = TRUE. Default=NULL.

extract_proxy_signal

Extract one astronomical cycle from the proxy record before anchoring (logical, TRUE or FALSE), with analyse_wavelet and extract_signal_stable. Default=FALSE.

proxy_period_up

Factor by which proxy_period_cycle is multiplied to give the upper (longest) period of the band extracted from the proxy record (numeric, > 1). Default=1.2.

proxy_period_down

Factor by which proxy_period_cycle is multiplied to give the lower (shortest) period of the band extracted from the proxy record (numeric, between 0 and 1). Default=0.8.

proxy_period_cycle

Period of the cycle to extract from the proxy record, in the unit of the first column of the record that is filtered (numeric, > 0); required when extract_proxy_signal = TRUE. Default=NULL.

pts

Number of points to the left and right of a value that the peak detection (max_detect, min_detect) compares it with (integer, >= 1): a value is a peak if it is higher (or lower) than all of them. Larger values give more certain peaks but may miss minor peaks. Default=3.

verbose

Ask for confirmation in the console after every selected tie point and print feedback (logical, TRUE or FALSE); with FALSE every selection is accepted directly. Default=FALSE.

time_dir

Direction of time in the proxy record (logical): TRUE if time increases with increasing depth/time values (e.g. borehole data that get older with depth), FALSE if it decreases (e.g. stratigraphic logs with 0 m at the base of the section); the proxy record is then plotted with a reversed axis. Default=TRUE.

genplot

Plot the proxy record and the astronomical solution with the selected tie points connected after the anchoring (logical, TRUE or FALSE). Default=FALSE.

Value

The output is a matrix with the 4 columns. The first column is the depth/time of the proxy tie-point. The second column is the time value of the astronomical solution tie-point. The third column is the proxy value of the proxy tie-point. The fourth column is the proxy/insolation value of the astronomical solution tie-point. If genplot is set to true then at plot of the of the achored points will be plotted

References

J. Laskar, P. Robutel, F. Joutel, M. Gastineau, A.C.M. Correia, and B. Levrard, B., 2004, A long term numerical solution for the insolation quantities of the Earth: Astron. Astrophys., Volume 428, 261-285. <doi:10.1051/0004-6361:20041335>

Laskar, J., Fienga, A., Gastineau, M., Manche, H., 2011a, La2010: A new orbital solution for the long-term motion of the Earth: Astron. Astrophys., Volume 532, A89 <doi:10.1051/0004-6361/201116836>

Laskar, J., Gastineau, M., Delisle, J.-B., Farres, A., Fienga, A.: 2011b, Strong chaos induced by close encounters with Ceres and Vesta, Astron: Astrophys., Volume 532, L4. <doi:10.1051/0004-6361/201117504>

J. Laskar,Chapter 4 - Astrochronology,Editor(s): Felix M. Gradstein, James G. Ogg, Mark D. Schmitz, Gabi M. Ogg,Geologic Time Scale 2020,Elsevier,2020,Pages 139-158,ISBN 9780128243602, <doi:10.1016/B978-0-12-824360-2.00004-8>

Zeebe, R. E. and Lourens, L. J. Geologically constrained astronomical solutions for the Cenozoic era, Earth and Planetary Science Letters, 2022 <doi:10.1016/j.epsl.2022.117595 >

Richard E. Zeebe Lucas J. Lourens ,Solar System chaos and the Paleocene–Eocene boundary age constrained by geology and astronomy.Science365,926-929(2019) <doi:10.1126/science.aax0612>

Zeebe, Richard E. "Numerical solutions for the orbital motion of the Solar System over the past 100 Myr: limits and new results." The Astronomical Journal 154, no. 5 (2017): 193. <doi:10.3847/1538-3881/aa8cce>

Stephen R. Meyers,Cyclostratigraphy and the problem of astrochronologic testing, Earth-Science Reviews,Volume 190,2019,Pages 190-223,ISSN 0012-8252 <doi:10.1016/j.earscirev.2018.11.015>

Examples

# \donttest{
if (interactive()) { # needs mouse input (identify())
# Use the grey_track example tracking points to anchor the grey scale data set
# of Zeeden et al., (2013) to the p-0.5t la2004 solution

grey_wt <-
 analyse_wavelet(
   data = grey,
   dj = 1/200,
   lowerPeriod = 0.02,
   upperPeriod = 256,
   verbose = FALSE,
   omega_nr = 8
 )
#Use the pre-tracked grey_track curve which traced the precession cycle
grey_track <- completed_series(
 wavelet = grey_wt,
 tracked_curve  = grey_track,
 period_up  = 1.25,
 period_down  = 0.75,
 extrapolate = TRUE,
genplot = FALSE
)
# Extract precession, obliquity and eccentricity to create a synthetic insolation curve

grey_prec <- extract_signal(
tracked_cycle_curve = grey_track[,c(1,2)],
wavelet = grey_wt,
period_up = 1.2,
period_down = 0.8,
add_mean = FALSE,
tracked_cycle_period = 22,
extract_cycle = 22,
tune = FALSE,
plot_residual = FALSE
)

grey_obl <- extract_signal(
 tracked_cycle_curve = grey_track[,c(1,2)],
 wavelet = grey_wt,
 period_up = 1.2,
 period_down = 0.8,
 add_mean = FALSE,
 tracked_cycle_period = 22,
 extract_cycle = 110,
 tune = FALSE,
 plot_residual = FALSE
)

grey_ecc <- extract_signal(
 tracked_cycle_curve = grey_track[,c(1,2)],
 wavelet = grey_wt,
 period_up = 1.25,
 period_down = 0.75,
 add_mean = FALSE,
 tracked_cycle_period = 22,
 extract_cycle = 40.8,
 tune = FALSE,
 plot_residual = FALSE
)

insolation_extract <- cbind(grey_ecc[,1],grey_prec[,2]+grey_obl[,2]+grey_ecc[,2]+mean(grey[,2]))
insolation_extract <- as.data.frame(insolation_extract)
insolation_extract_mins <- min_detect(insolation_extract,pts=3)

#use the astrosignal_example to tune to which is an \cr
# ETP solution (p-0.5t la2004 solution)
astrosignal_example <- na.omit(astrosignal_example)
astrosignal_example[,2] <- -1*astrosignal_example[,2]
astrosignal <- as.data.frame(astrosignal_example)

#anchor the synthetic insolation curve extracted from the grey scale record to the insolation curve.

anchor_pts <- astro_anchor(
astro_solution = astrosignal,
proxy_signal = insolation_extract,
proxy_min_or_max = "min",
clip_astrosolution = FALSE,
astrosolution_min_or_max = "min",
clip_high = NULL,
clip_low = NULL,
extract_astrosolution  = FALSE,
astro_period_up  = NULL,
astro_period_down  = NULL,
astro_period_cycle  = NULL,
extract_proxy_signal  = FALSE,
proxy_period_up  = NULL,
proxy_period_down  = NULL,
proxy_period_cycle  = NULL,
pts=3,
verbose=FALSE, #set verbose to TRUE to allow for anchoring using text feedback commands
genplot=FALSE
)}# }