Box coring artifacts in sediments affected by a waste water outfall

Area of Science:

• Marine geology
• Sedimentology
• Environmental science

Background:

• Sediment loss and core shortening during sampling are common issues.
• High organic matter content increases sediment porosity and reduces mechanical resistance.
• Previous studies have overlooked the impact of high porosity on coring artifacts.

Purpose of the Study:

• To demonstrate box coring artifacts in Palos Verdes shelf sediments.
• To highlight the role of organic carbon-enriched sediments in causing these artifacts.
• To emphasize the implications for estimating sediment and pollutant accumulation rates.

Main Methods:

• Analysis of surface sediment porosity variations.
• Investigation of sediment properties on the Palos Verdes shelf.
• Assessment of organic carbon content in relation to sediment structure.

Main Results:

• Box coring artifacts were observed in Palos Verdes shelf sediments.
• High porosity layers, resulting from past organic carbon loads, were identified.
• Sediment loss and core shortening were linked to these high porosity zones.

Conclusions:

• High porosity sediments can lead to significant underestimation of sedimentation rates.
• The findings have critical implications for reconstructing pollutant fluxes in coastal environments.
• Accurate assessment of sediment accumulation histories requires accounting for coring-induced artifacts.