Combined classification and source apportionment analysis for trace elements in western Philippine Sea sediments.

Area of Science:

• Environmental geochemistry
• Marine sediment analysis
• Trace element studies

Background:

• Trace elements are crucial for classifying variables and samples, and for source apportionment studies.
• Integrating these approaches is uncommon, limiting a comprehensive understanding of element origins and distribution.

Purpose of the Study:

• To merge trace element grouping, sample clustering, and source identification for an integrated understanding of trace element origin and distribution in the western Philippine Sea.
• To apply a multiperspective methodology for improved environmental studies.

Main Methods:

• Utilized a self-organizing map (SOM) for nonlinear clustering of 26 trace elements into four groups and sediment samples into five clusters.
• Employed positive matrix factorization (PMF) for nontraditional factor analysis to identify potential pollution sources.
• Integrated SOM visualization and clustering with PMF outputs for comparative analysis.

Main Results:

• SOM successfully classified trace elements and sediment samples, revealing distinct geographic clusters associated with specific element groups.
• PMF identified five significant sources: Taiwan Island land mass, Taiwan anthropogenic emissions, South China Sea nutrient export, deep ocean mineral attachment, and Luzon Islands biogenetic/riverine inputs.
• Spatial distribution of sample clusters correlated with PMF-identified source contributions, demonstrating consistency between methods.

Conclusions:

• The integrated approach provides a robust understanding of trace element origins and distribution in marine sediments.
• The study validates the consistency of classification and source identification, enhancing multiperspective environmental analysis.
• This methodology offers a powerful tool for marine geochemistry and pollution source tracking.