Spatial Patterns of Sediment Accumulation on a Holocene Carbonate Tidal Flat, Northwest Andros Island, Bahamas
Entry ID:
RSMAS_GR002
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Summary
Abstract:
To characterize spatial patterns of sedimentation and analyze the morphology of part of the modern tidal flats of northwest Andros Island in the Bahamas, this study integrated remote sensing, geographic information systems (GIS), and carbonate sedimentology. The fundamental data are a Landsat TM image that has been classified to create a thematic map of eight subfacies, interpreted to represent a ... distinct tidal-flat subenvironment such as adjacent marine, exposed
levee-beach ridge, pond, and algal marsh. Spatial statistics of the thematic
map characterize the patterns of sediment accumulation. Quantitative analysis
highlights several interesting results concerning subfacies character and
distribution: (1) of the eight mapped subfacies, low algal marsh is most
widespread, representing 27.5% of the total area, whereas exposed levee-beach
ridge is the least widespread, accounting for 10% of the area; (2) the patches
of different subfacies have different shape complexities, with low algal marsh,
high algal marsh, and mangrove ponds being the least complex and exposed
levee-beach ridge being the most complex; (3) Markov chain analysis suggests
that lateral transitions between different subfacies are highly ordered; (4)
frequency distribution of subfacies patch area and lacunarity (gap size
distribution) data exhibit power law relationships over several orders of
magnitude, consistent with fractal characteristics; and (5) mean subfacies
patch size is highly correlated with mean distance to a tidal channel.
The fractal nature of patch size and gaps between facies illustrate that on
this tidal flat neither the size nor the spatial distribution of subfacies has
a characteristic scale. This statistical behavior is consistent with the
presence of self-organization, or emergence of pattern in the absence of a
template or external forcing. The statistical self-organization on the tidal
flat is the cumulative expression of local processes, but it becomes apparent
only through analysis of the whole system. These results are inconsistent with
models suggesting that tidal flats include a migrating complex of randomly
distributed, randomly sized subenvironments. Ancient successions that include
random patterns may reflect the more pronounced influence of forces external to
the sedimentary system, instead of an absence of those forces. The purpose of
this study is to characterize spatial patterns of sedimentation and analyze the
morphology of part of the modern tidal flats of northwest Andros Island in the
Bahamas, through the integration of remote sensing, geographic information
systems (GIS), and carbonate sedimentology.
Spatial Data Organization Information -
Indirect Spatial Reference: All locations were determined using a UTM/
latitude-longitude system.
Direct Spatial Reference: Point Spatial Reference Information
- Horizontal Coordinate System Definition - Geodetic Model: 
Geographic Coverage
(Click for Interactive Map)
Spatial coordinates
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N: 25.1
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S: 24.15
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E: -77.58
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W: -78.37
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Data Set Citation
Dataset Originator/Creator:
Dr. Gene Rankey
Dataset Title:
Spatial patterns of sediment accumulation on a holocene carbonate tidal flat, northwest Andros Island, Bahamas
Dataset Series Name:
Journal of Sedimentary Geology
Dataset Release Date:
2002
Dataset Release Place:
Tulsa, Oklahoma, USA
Dataset Publisher:
SEPM-Society for Sedimentary Geology
Issue Identification:
GR-002
Quality
The various multibeam datasets were processed within acquisition software by the originating agencies in order to correct for sound velocity variations within the water column and the removal of noise. No account has been taken of tidal range, so all depth data is assumed to have a vertical datum of mean sea-level (MSL). The final DEMs conform to Order 2 of the International Hydrographic ... Organisation (IHO) Standards for Hydrographic Surveys Special Publication 44 - 5th Edition February 2008. Both Total Horizontal Uncertainty (THU) and Total Vertical Uncertainty (TVU) increase according to depth, so the maximum allowable THU is 30m up to 100m depth, 70m up to 500m depth, 120m up to 1000m depth, 220m up to 2000m depth, and so on. Realistically, however, the accuracy of GPS used for positioning during modern surveys is far better than the maximum allowable THU for Order 2 surveys, and so the THU figures quoted here are very conservative. The maximum allowable TVU is 2.5 m up to 100 m; 11.5 m up to 500 m depth; 23 m up to 1000 m depth; 46 m up to 2000 m depth and so on.
The data were last updated on May 11, 2011.
Access Constraints
The data are available for non-commercial use.
Use Constraints
This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).
Users of the gvdem grid must include the following references in any subsequent publications using this dataset:
De Santis, L., Brancolini, G., Accettella, D., Cova, A., Caburlotto, A., Donda, F., Pelos, C., Zgur, F., Presti, M., 2007. New insights into ... submarine geomorphology and depositional processes along the George V Land continental slope and upper rise (East Antarctica). In: A.K. Cooper and C.R. Raymond (Editors), 10th International Symposium on Antarctic Earth Sciences, August 26-31 2007. Scientific Committee on Antarctic Research, Santa Barbara, U.S.A., pp. 1-5.
Beaman, R.J., O'Brien, P.E., Post, A.L., De Santis, L., 2011. A new high-resolution bathymetry model for the Terre Adelie and George V continental margin, East Antarctica. Antarctic Science 23(1), 95-103. doi:10.1017/S095410201000074X
Data Set Progress
COMPLETE
Distribution
Distribution Media:
HTTP
Distribution Size:
193 MB
Distribution Format:
ArcInfo ascii
Fees:
Free
Distribution Media:
HTTP
Distribution Size:
34.3 MB
Distribution Format:
ArcInfo ascii
Fees:
Free
Distribution Media:
HTTP
Distribution Format:
ArcInfo ascii
Fees:
Free
Personnel
Role:
INVESTIGATOR
Role:
TECHNICAL CONTACT
Role:
DIF AUTHOR
Phone:
+61 7 4042 1693
Fax:
+61 7 4042 1284
Email:
robin.beaman at jcu.edu.au
Contact Address:
James Cook University PO Box 6811
City:
Cairns
Province or State:
QLD
Postal Code:
4870
Country:
Australia
Publications/References
Beaman, R.J., O'Brien, P.E., Post, A.L., De Santis, L. (2011), A new high-resolution bathymetry model for the Terre Adelie and George V continental margin, East Antarctica., Antarctic Science, 1, 23, 95-103, doi:doi:10.1017/S095410201000074X
Creation and Review Dates
DIF Creation Date:
2009-03-09
Last DIF Revision Date:
2011-05-17
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