Shoreline change rates along Samborombón Bay, Río de la Plata estuary, Argentina

Bacino, Guido; Dragani, Walter C.; Codignotto, Jorge Osvaldo; Pescio, Andrés Esteban; Farenga, Marcelo

doi:10.1016/j.ecss.2020.106659

Cited by 18 publications

(10 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The major river flowing into the bay is the Río Salado, draining a large part of the Buenos Aires Province but characterized by inefficient runoff because of its extremely low gradient. Both tips of the bay are undergoing erosion (up to ca 12 m/year), whereas suspended mud largely supplied from the Río de la Plata (Moreira et al ., 2013) is transported by currents towards the centre of the bay contributing to locally rapid marshland expansion (up to ca 21 m/year; Bacino et al ., 2020).…”

Section: The Argentine Passive Marginmentioning

confidence: 99%

From Patagonia to Río de la Plata: Multistep long‐distance littoral transport of Andean volcaniclastic sand along the Argentine passive margin

et al. 2021

View full text Add to dashboard Cite

Large sediment masses are transferred over many hundreds of kilometres along the coast of passive continental margins worldwide. The relevance of such a phenomenon for source-to-sink studies, environmental issues, and coastal management remains largely unperceived. This study traces the paths of volcaniclastic sand along ca 2170 km of the Argentine coast and documents a 760 km long cell of littoral transport extending from the formerly larger R ıo Colorado delta to the edge of the R ıo de la Plata mouth. During deglaciation stages and humid periods of the Pleistocene, a much greater sediment volume than today was transferred by the Desaguadero and Colorado rivers from the highest-relief tract of the Andean Cordillera to the Atlantic Ocean. Amphibole-rich sand originally supplied by the R ıo Desaguadero is being recycled today from Pampean lowlands to feed the beaches along R ıo de la Plata southern shores, whereas pure quartzose sand of R ıo Paran a is found only adjacent to its prograding delta. Augite-rich sand supplied by the R ıo Colorado is dominant along the coast of the Buenos Aires Province, where it mixes locally with coarser-grained quartz-rich detritus recycled in the urbanized Mar del Plata area. Hypersthene-rich sand of the R ıo Negro is dispersed both north and south of the mouth, where heavy-mineral-rich lag deposits are formed in areas of accelerated erosion and retreating sea cliffs. Changes of mineralogical signatures during long-distance littoral transport are largely ascribed to local supply from coastal erosion or hydrodynamic effects rather than to selective breakdown of labile grains. Whereas the relative abundance of amphibole and pyroxene is largely independent of transport distance, olivine is depleted both in the northern part of the Colorado littoral cell and south of the R ıo Negro mouth, which is chiefly ascribed to dilution by recycling of Neogene sediments that have undergone early intrastratal dissolution rather than to mechanical loss.Keywords Amphibole Color Index, Colorado and Negro rivers, durability of olivine and pyroxene, longshore sand transport, passive-margin sediments, R ıo de la Plata estuary, R ıo Desaguadero, sedimentary petrology, Southern Hemisphere swells.

show abstract

Section: The Argentine Passive Marginmentioning

confidence: 99%

From Patagonia to Río de la Plata: Multistep long‐distance littoral transport of Andean volcaniclastic sand along the Argentine passive margin

et al. 2021

View full text Add to dashboard Cite

show abstract

“…On the other hand, accretion trends between 1944 and 2018 were identified in Punta Piedras bay-tip (D’Amico, 2020), although Bacino et al (2020), reported negative values during 1964–2016, and the northern sector of the Juan Gerónimo between 1964 and 2010 (Bacino et al, 2020). Along the bay coast, the mouths of the Salado and Samborombón rivers showed an accretion trend during 1931–2018 (D’Amico, 2020), as well as the Channel 18 mouth for the period 1964–2017 (Bacino et al, 2020), and south of the mouth of Channel 1 between 1964 and 2017 (Bacino et al, 2020) (see sites in Figure 1). Nevertheless, trends vary by sector.…”

Section: Introductionmentioning

confidence: 99%

“…Nevertheless, trends vary by sector. Accretion trends are predominant in the central area of the bay, while erosion trends are detected near the bay tips, in coincidence with Bacino et al (2020). Results are different according to each author due to differences in the selected sites and time-lapse, the selection and geo-referencing of the images (Bacino, 2018), the shoreline proxy, and the shoreline digitizing criteria.…”

Section: Introductionmentioning

confidence: 99%

“…Regarding shoreline changes, they were determined for different sites (Figure 1) and periods along Samborombón bay. For instance, erosive trends were detected in Punta del Indio between 1943 and 2013 (Cellone et al, 2016) 1964–2017 (Bacino et al, 2020), and 1956–2018 (D’Amico, 2020), and in the southern sector of Juan Gerónimo between 1964 and 2010 (Bacino et al, 2020). Both sectors are located north and south of the northern tip of the bay, respectively (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

“…Both sectors are located north and south of the northern tip of the bay, respectively (Figure 1). South of the bay, negative trends were detected in the Ajó river mouth between 1964 and 2017 (Bacino et al, 2020) and the estuarial sector of Punta Rasa between 1937 and 2018 (D’Amico et al, 2019) (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Long-term shoreline evolution (Late-Holocene – 2018) of the Channel 15 coast (Samborombón bay, NE – Buenos Aires province, Argentina)

et al. 2022

View full text Add to dashboard Cite

Here we present an investigation with the aim of reconstructing the shoreline evolution and geomorphological changes in the central zone of Samborombón bay (Channel 15, Buenos Aires province, Argentina) during the period 2700 cal yr BP to recent times. Palynological, geomorphological and historical imagery and proxy-data analyses were combined to reconstruct the shoreline evolution and paleo-environmental changes. Palynological material (pollen and non-pollen palynomorphs -NPP-) was recovered from a continuous 117 cm long sedimentary profile extracted from an outcrop at the northern margin of Channel 15. Relict landforms, including paleo- shorelines, were reconstructed by applying enhancing filters to a Spot 6 image from 2015. Historical shorelines were identified in high-definition images (aerial and satellite imagery) between 1968 and 2018, but also by using the marsh vegetation edge as a shoreline proxy. Shoreline change was quantified using the Net Shoreline Movement and Weighted Linear Regression algorithms in ArcMap 10.1. Results based on the palynological analysis for the period 2700–2740 BP, show the passage from subtidal-intertidal to supratidal environment with influence of brackish to fresh-waters, where paleo-shorelines imprint was recognized developing over a tidal plain that was grading to marshes. Results based on aerial and satellite imagery for the period 1968–2018 show shoreline retrocession only immediately at the north of the channel mouth, while the rest of the coast prograded toward the estuary. These processes indicate that new marshes – and, therefore, wetlands – are constantly developing at the edge of Samborombón bay.

show abstract

Initial morphological responses of coastal beaches to a mega offshore artificial island

Liu

Cai

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

Mega offshore artificial islands (MOAIs) can lead to large-scale and significant coastal responses, which have been poorly documented. In this study, coastal changes of an 8 km-long beach along Haikou Bay, China, were analysed to advance the understanding of the potential morphological responses to a MOAI with a diameter of 2.3 km.Field surveys of beach profiles and shorelines in different years were used to reveal the initial coastal changes after the construction of the MOAI. The results showed that the beach in the leeside of the MOAI accreted seaward, whereas the adjacent beaches retreated, which was revealed to be closely related to the alteration in longshore sediment transport patterns induced by the presence of the MOAI. As predicted by empirical equations, a large salient (hundreds of metres of amplitude) rather than a tombolo would be formed on the leeside of the MOAI if there is sufficient sediment supply. From the initial morphological observation, it was indicated that the final total beach length affected by this MOAI will be larger than 6200 m. However, based on predictive equations derived from small-scale offshore obstacles (SCOOs), this value was less than 6200 m. It is likely that the geometric properties induced by MOAIs may not be estimated by these empirical equations derived from SCOOs. Moreover, a great difference in salient equilibrium time was highlighted between them. The timescale of salient equilibrium for this MOAI was likely on an order of hundred years of magnitude, while that for SCOOs were generally less than 10 years, which was related to the water depth of the obstacle position. This study provides new insights into the differences in coastal change between the MOAI and SCOOs and will help local governments adopt appropriate coastal sediment management strategies from a regional scale and a longer timescale in the face of increasing human activities.

show abstract

Shoreline change rates along Samborombón Bay, Río de la Plata estuary, Argentina

Cited by 18 publications

References 54 publications

From Patagonia to Río de la Plata: Multistep long‐distance littoral transport of Andean volcaniclastic sand along the Argentine passive margin

From Patagonia to Río de la Plata: Multistep long‐distance littoral transport of Andean volcaniclastic sand along the Argentine passive margin

Long-term shoreline evolution (Late-Holocene – 2018) of the Channel 15 coast (Samborombón bay, NE – Buenos Aires province, Argentina)

Initial morphological responses of coastal beaches to a mega offshore artificial island

Contact Info

Product

Resources

About