Interpretative modelling of a geological cross section from boreholes: sources of uncertainty and their quantification
We conducted a designed experiment to quantify sources of uncertainty in geologists' interpretations of a geological cross section. A group of 28 geologists participated in the experiment. Each interpreted borehole record included up to three Palaeogene bedrock units, including the target unit...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-11-01
|
| Series: | Solid Earth |
| Online Access: | http://www.solid-earth.net/5/1189/2014/se-5-1189-2014.pdf |
| Summary: | We conducted a designed experiment to quantify sources of uncertainty in
geologists' interpretations of a geological cross section. A group of 28
geologists participated in the experiment. Each interpreted borehole record
included up to three Palaeogene bedrock units, including the target unit for
the experiment: the London Clay. The set of boreholes was divided into
batches from which validation boreholes had been withheld; as a result, we
obtained 129 point comparisons between the interpreted elevation of the base
of the London Clay and its observed elevation in a borehole not used for that
particular interpretation. Analysis of the results showed good general
agreement between the observed and interpreted elevations, with no evidence
of systematic bias. Between-site variation of the interpretation error was
spatially correlated, and the variance appeared to be stationary. The
between-geologist component of variance was smaller overall, and depended on
the distance to the nearest borehole. There was also evidence that the
between-geologist variance depends on the degree of experience of the
individual. We used the statistical model of interpretation error to compute
confidence intervals for any one interpretation of the base of the London
Clay on the cross section, and to provide uncertainty measures for decision
support in a hypothetical route-planning process. The statistical model could
also be used to quantify error propagation in a full 3-D geological model
produced from interpreted cross sections. |
|---|---|
| ISSN: | 1869-9510 1869-9529 |