ANTHROPLAST: Mud depocenters contain ANTHROpocene microPLASTic and bulk organic content sedimentary signatures inferred from acoustics and paleoenvironmental methods
Abstract
The geological time scale provides a reference framework where different events in the Earth s history are represented in sedimentary deposits with features that distinguish each of them. The Quaternary represents the last 2.58 million yr and is subdivided into the Pleistocene and Holocene. The Pleistocene is colloquially known as the Ice Age, covering the most recent period of glaciations. Aglobal increase in temperature and consequent deglaciation marks the transition from the Pleistocene to the Holocene, which occurred approximately 11,700 years ago, and was characterized by a global rise in sea level. The term Anthropocene, although not yet officially recognized by the International Union of Geological Sciences, refers to a new geological epoch after the Holocene, characterized by the predominance of the anthropic footprint in the sedimentary record. This is because it is widely accepted that the global environment has been clearly modulated by human activity, and such activitiesare indeed reflected within the stratigraphic record. Several authors already reported that Holocene sediments are clearly different from those of the Anthropocene, because of a combination of aluminum, plastics, concrete, metals, pesticides and particles from fossil fuel combustion. In this regard, the year 1950 CE was proposed as the beginning of the Anthropocene, which coincides with the so-called "Great Acceleration" that is characterized by a global growth in economic and technological activities, together with an increase in population, consumption of resources and absence of consistent conservation strategies. Among several contaminants related to the Anthropocene, plastic pollution in marine regionsis currently one of the most critical environmental issues affecting the world. Global plastic production has dramatically increased over the last decades, as did the amount of plastic waste entering the ocean, which is now ubiquitous throughout marine systems inboth surface waters and the sea bottom. In addition, the incoming flux of plastic is expected to increase by an order of magnitude in the next decade. At microscopic scale, microplastics (MPs < 5 mm) are virtually recorded in all natural environments due to theirhuge production, exaggerated use, inadequate disposal, persistence and easy dispersal. Moreover, it is practically impossible to remove them from the sedimentary environment. Thus, MPs longevity, dispersion, and accumulation capacity in sediments support their practical utility as a proxy material for dating stratigraphic sequences, being therefore a stratigraphic marker of the Anthropocene notably used at a global scale. The objective of this proposal is to analyze the MPs distribution in several sediment cores from the Patos-Mirim System and propose the consideration of MPs as a stratigraphic and chronological marker of the Anthropocene onset in South-East South America. The sediment cores will be retrieved from mud depocenters identified byacoustic methods, using a similar approach to the study of geologic characteristics and geophysical properties of sediments from the New England mud patch off New York,USA, as reported within item 3 of this proposal. In addition, acoustic methods will be used to trace bulk modulus distribution as aproxy for organic content and microplastics. The project will be develop based on an already existing strong collaboration between the Universidad de la República (Uruguay) and Universidade Federal do Rio Grande (Brazil). In addition, a collaboration with both Knobles Scientific and Analysis and University of Texas at Austin (USA) will be established to undertake this proposal, which contemplates bringing cutting edge acoustic technologies from USA to Brazil for field work within the six mud depocenters of Patos-Mirim Lagoon.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 11, 2024
- Source ID
- N629092412038
Entities
People
- Felipe Garcia-rodriguez
Organizations
- Office of Naval Research
- United States Navy