Physical Changes in the Patagonian Shelf

MARTIN SARACENO; JACOBO MARTIN; DIEGO MOREIRA; JUAN PABLO PISONI; MARIANO TONINI

Global Change in Atlantic Coastal Patagonian Ecosystems

Springer

Año: 2022; p. 43 - 71

he coastal marine regions are expected to be the most vulnerable to the effects of climate change, such as variations in sea level, extreme events, and temperature changes, among others (IPCC 2014). Coastal ecosystems are already affected by the combination of these factors and by the adverse effects of human activities (Oppenheimer et al. 2019). The physical changes observed in the region that extends from the Médanos point (36.9°S) to Tierra del Fuego (55°S) and includes the waters from the coastline to the continental shelf-break are described in this chapter, with particular emphasis in the coastal area. The Patagonian shelf (Fig. 1) can be divided in three regions from the coast to the open ocean: we define here the inner shelf as the portion of the sea that goes from the coastline up to the 50 m isobath, including all the gulfs and channels; the outer shelf is considered as the 40 km fringe closest to the shelf-break and the middle shelf as the region included between the inner and the outer shelf regions. The inner shelf is characterized by distinct morphological, climatic, and oceanographic features. With more than 3000 km of coasts, the region encompasses four distinct subregions: Buenos Aires shelf, North Patagonian gulfs, San Jorge gulf, and the Southern Patagonian shelf (SPS). The SPS includes the Beagle channel and the Magellan strait. The chapter is organized as follows: data and methods are presented followed by the description of the middle and outer con- tinental shelf, along with the analysis of the observed trends of sea surface tempera- ture, chlorophyll a (hereafter Chl a), and sea level height. The four subregions are then described individually, followed by highlights of the more relevant results presented.