Aggregating Marine Geological Data 
on a National Scale
Chris Jenkins 
The University of Sydney (Australia)
Introduction

The problem with combining marine geological data from years of sampling and research is that it is so diverse. The data has been collected by geologists, engineers, surveyors and ecologists, all with different techniques and project priorities. 

The result is that a usual Relational Database (RDBMS) type of aggregation is not very useful: the distribution of data across the sample/parameter matrix is too sparse. Instead we advocate a Data Mining technique which pre-processes the data before incorporation into RDBMS and GIS (Geographic Information Systems).

Australian EEZ

Australia has an EEZ that occupies 1/12 the globe's area and now has a working database of seafloor characteristics that is being used by engineers, ecologists, researchers, defence, policy makers and the community at large for mapping, statistics, query and input to models. The database holds over 120,000 attributed sample sites from over 289 datasets and goes by the name auSEABED. A parallel structure has been built for the US west coast in collaboration with the USGS (usSEABED) and independently for SE Asia, all using the core software and data structure which is bundled as dbSEABED

The benefits of aggregating the multiple datasets that come from present (and past) seabed sampling activities is manifest. In the Australian and US cases we have applied the outputs to these issues: 
i) planning offshore marine parks and 

conservation areas 
ii) tactics planning in naval mine countermeasures 
iii) sonar prediction, both for naval systems and for whale communication distances 
iv) pipeline route planning, including the question of self-burial 
v) fisheries habitat assessments involved in regulation of activities 
vi) research cruise planning, for example for stratified sampling 
vii) seabed stability modelling, under wave, tide and current regimes 
viii) input to ocean and inshore nutrient modelling 
ix) guiding sonar searches for wrecks and seabed obstacles.

The data structure

Basically, the data - more or less in the original terms and units of the original authors - is held in a mineable set of Data Resource Files. Although they are in ASCII they are not flat in structure, being more like an XML type tree-d structure. The ASCII format is important: a vendor-independent legacy of data is created that can be worked on scientifically by commercial- and research-type software packages. 

A wide range of data is held: lithological, textural, compositional, geochemical, petrological, geotechnical, geoacoustic, sedimentary structures, benthic biota. Although we concentrate on point-sample data, polygon and polyline formats are treatable. Down-core samplings and analyses are also handled appropriately. As time goes on, the resolution of the database increases by the addition of more data and construction of extra data mining  

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