Time-Scale Adjustment

Example: Time scale adjustment of borehole data

The adjustment of time scales of geological data series to a geological reference time series is of major interest in many investigations. For example, geophysical borehole data should be correlated to a given geological profile whose time scale is known in order to achieve an age-depth function or the sedimentation rate for the borehole data. Cross recurrence plots (CRPs) are highly recommended for such problems, because they obtain relationships between the time scales of different time series. In contrast to the common visual matching, CRPs offer an objective and automatic way to get the relationship between the time/ depth scales.

In the following example we present an adjustment of the scales of two different lake sediment cores from the Lago di Mezzano (Italy), by using rock magnetic data.

Cross recurrence plot based on the normalized sediment parameters (NRM and kLF) and an additional embedding dimension of m = 3 (τ = 1, ε = 0.05). The depth-depth-curve is marked with red; this non-parametrical function can be used in order to re-adjust the time scales of the two profiles.

The adjusted lake sediment data.

Reference:

Marwan, N., Thiel, M., Nowaczyk, N. R.: Cross Recurrence Plot Based Synchronization of Time Series, Nonlin. Proc. Geophys., 9, 2002, 325-331, url:www.copernicus.org/EGU/npg/9/325.htm, Article (PDF).

Application Potentials:

• time scale adjustment of borehole data
• dendrochronology
• search of matching sequences in DNA strings or speech data