Cesar Andrade

University of Lisbon | UL · Department of Geology

Embayed beaches, characterized by their distinctive planform curvature, are a common feature along coastlines worldwide. This study introduces a novel approach to describe bay shape that extends our understanding about the processes that control embayed beach development. The novel approach was thoroughly tested against one-line models and applied...

Caldeiras da Ribeira Grande is one of the degassing areas of Fogo, a trachytic central volcano located at São Miguel Island (Azores archipelago). Recently, new steam emissions, soil CO2 and temperature anomalies developed towards the inhabited area, causing high indoor CO2 values and affecting the vegetation and several small animals that were foun...

To investigate unexplored areas and apply methodologies suitable for monitoring volcanic activity, a pioneer study was undertaken in the crater lagoon of Vila Franca do Campo Islet to identify possible CO 2 degassing zones in the marine environment. This study was carried out using a floating accumulation chamber, which to the best of our knowledge...

The well-known 1755 CE Lisbon tsunami caused widespread destruction along the Iberian and northern Moroccan coastlines. Being affected by the powerful 1755 CE Lisbon tsunami, the southwestern Algarve shelf provides environments for detecting offshore tsunami imprints. Our multidisciplinary investigations (hydroacoustics, sedimentology, geochemistry...

This study focused on 13 water samples collected from two of the main active volcanoes (Furnas and Fogo) at São Miguel, Azores. Based on the major element composition, the waters are classified into Na-HCO3 and Na-Cl types. While the concentrations of chloride seem to reflect the contribution of sea salt aerosols, the behavior of the main cationic...

Salt marshes are highly valued coastal environments for different services: coastline protection, biodiversity, and blue carbon. They are vulnerable to climate changes, particularly to sea-level rise. For this reason, it is essential to project the evolution of marsh areas until the end of the century. This work presents a reduced complexity model...

Meeting current coastal and ocean sustainability challenges requires wiser governance. Scientists, as knowledge generators, have the responsibility to contribute to a more informed society, which in turn will be able to support better decisions. However, inspiring the audience and assuring their receptivity to often complex scientific message is no...

RESUMO Compararam-se as distâncias de inundação alcançadas na costa algarvia pelo tsunami de 1755 e a variação da espessura dos depósitos correspondentes. Sugere-se que o espaço de acomodação controla a relação entre o limite terrestre do depósito e a extensão máxima da inundação, com valores entre 20% (espaços de acomodação menores) e de 50% (espa...

Costa da Caparica seafront margins a low-lying strand-plain where conflicts have coexisted throughout the last seven decades between development and conservation (cf. Veloso-Gomes et al. 2007; Pinto et al. 2007). Development grew exponentially after the 1950’s, bringing housing and other infrastructures too close to the shoreline, and this was acco...

Since the early 2000’s the strategy of intervention switched to beach nourishment and dune restoration, adopted as adaption methods to cope with impacts of long- term erosion trend, storm-driven inundation, damages to hard engineering structures and preservation of beach recreational value. Main objectives of this study are the characterization of...

Groundwater contributes to the maintenance of the functioning of ecosystems, through aspects related to hydrodynamics and chemical composition. Groundwater-dependent ecosystems (GDE) also offer a wide spectrum of ecosystem services to populations; therefore, their identification and mapping, which is the focus of the present paper, is of high value...

The Cabo Verde Archipelago holds a remarkable sedimentary record of tsunami inundations, as highlighted by recent finds on Santiago and Maio Islands. Santiago, in particular, constitutes an exceptional site to study in detail the proximal impacts of the megatsunami(s) triggered by the well-known catastrophic flank collapse of Fogo volcano (~60 km t...

Tephra fall is among the set of hazardous phenomena associated with volcanic activity that can impact water resources and services. The aim of this paper is to characterize the potential impacts of tephra fall on the groundwater-fed water supply system of Ponta Delgada (São Miguel, Azores) by comparing two scenarios of explosive eruptions. Vulnerab...

Understanding time scales of beach response (erosion and recovery) to extreme storms is particularly relevant for management of coastal land and risk. Observations show that rock-bounded platform beaches are generally remarkably stable and only occasionally respond to extreme storm wave forcing with abrupt morphological changes. The present work ai...

Current coastal protection strategy in Portugal defines beach and shoreface nourishment as a valid measure to mitigate coastal erosion in some erosional hot-spots, being considered as an adaptation measure under the present climate change scenario, including the impacts of sea level rise. However, scant objective data on shoreface nourishments are...

No âmbito do projecto Lisbon Stories recolheram-se em contexto de obra amostras de sedimento da antiga margem estuarina do Tejo. Os sedimentos foram analisados para diversos proxies e a interpretação dos resultados contribuiu para melhor compreender a evolução desta zona ribeirinha nos últimos milénios. Nas áreas de amostragem encontraram-se testem...

Evidence for frequent, large landslides on the flanks of the volcanic edifices forming the Canary Islands include outstanding landslide scars and their correlative submarine and subaerial rock and debris avalanche deposits. These landslides involved volumes ranging from tens to hundreds of km3. The sudden entry of large volumes of rock masses in th...

Development of science-based coastal policies and strategies that effectively cope with coastal change and risk requires transfer of scientific knowledge beyond the scientific community, and its integration in management processes. However, scientists frequently convey their message to non-specialized audiences resourcing to their own empirical exp...

Plain Language Summary The precise location of the seismic source of 1755 CE Great Lisbon earthquake is still uncertain. The aim of this work is to use an onland sedimentary record in southern Portugal to test and validate seismic sources for the earthquake. To achieve this, tsunami deposit thicknesses from over 150 cores collected at Salgados in s...

The world's coastlines are dominated by rocky coasts, where embayed and shore platform beaches develop. The intrinsic characteristics of these environments make them extremely vulnerable to changes in oceanographic forcing. Assessing long-term beach evolution can be a challenging task because coastline indicators were developed for wide and low-lyi...

Aim: Temperate forests are currently facing multiple stresses due to climate change, biological invasions, habitat fragmentation and fire regime change. How these stressors interact with each other influences how, when and whether ecosystems recover, or whether they adapt or transition to a different ecological state. Because forest recovery or col...

Sete Cidades Lake (São Miguel Island, Portugal) is subdivided into two interconnected branches: the Green Lake and Blue Lake. The lake has an area and maximum depth of 4.39 km² and 29.5 m (Blue Lake), respectively, with evidence of eutrophication, particularly in the northern area of the Green Lake. In this study, we conducted a sampling survey dur...

Tsunami backwash is a relevant factor for the final tsunami deposit configuration. The backwash flow hydraulics are believed to behave differently from inflow due to channelized concentration of the backwash turbid flows transporting sediments seaward and possibly into deep water. It is important to stress the stronger preservation potential in the...

This paper reviews the evidence for onshore sedimentary imprints of tsunami inundation known from the geological record of the Atlantic basin. The central aim of the paper is to offer a broad overview on the main deposits and key localities that have been documented along the Atlantic coastlines, and which attest to the local or regional impact of...

Tsunamis and storms cause considerable coastal flooding, numerous fatalities, destruction of structures, and erosion. The characterization of energy and frequency associated with each wave contribute to the risk assessment in coastal regions. Coastal boulder deposits represent a physical proof of extreme inundation and allow us to study the effects...

A geochemical study was carried out at Fogo Lake during June 2016, in one of the deepest lakes on São Miguel Island, as well as on small associated pond, in order to identify possible anomalous degassing areas. Fogo Lake is located inside the summit caldera of Fogo Volcano, one of the three active central volcanoes that dominate São Miguel geology....

Water-covered areas may lead to gaps in surface electromagnetic surveys, causing reduced resolution and, in consequence, increased uncertainty in derived subsurface models. We describe a boat-towed floating central loop time-domain electromagnetic technique which allows mitigating this problem. It facilitates obtaining data with a spatial sampling...

Tsunami deposits are the primary source of information on (past) large tsunami events and thereby are crucial for accurate hazard assessments. Tsunami deposits studies have developed over the last three decades, but this is still a young geoscience discipline. Following the 5th International Tsunami Field Symposium in 2017 an opportunity arose to p...

Between ca.8400-7000 cal BP Late Mesolithic communities occupied the Sado valley embankments, upstream Alcácer do Sal, Portugal. The consumption of marine resources is attested by the shell waste abandoned in several sites (known as shell middens) and later confirmed by isotopic analyses on bone collagen from individuals buried in these locations....

A zona costeira está sujeita a fenómenos de galgamento que podem pôr em causa a segurança de pessoas e bens. Nesse sentido, é necessário desenvolver métodos de previsão fiáveis que antecipem estas ocorrências. Apresenta-se uma estratégia de modelação do galgamento em zonas costeiras urbanizadas através da aplicação dos modelos SWAN e SWASH. Os resu...

Introduction Recent work on the central Algarve (south Portugal) has revealed a complex coastal stratigraphic sequence on the Almargem lowland. This sector of the coast is characterized by strong coastline recession, previous studies suggesting that it has retreated over 200 meters over the last 3 centuries. The aim was to identify signature of ext...

Naturally and artificially breached tidal inlets can promote fast morphological changes along the adjacent detrital barriers, as they evolve in response to the contemporaneous wave regime. Inlet migration results in downdrift barrier erosion, while updrift sand accumulation and concomitant barrier extension are commonly observed. This study address...

{Link to temporary free access: https://authors.elsevier.com/a/1Y~upB8cckOH9} Sustainable management of insular beaches, that are critical to tourism-based economies, depends on sound understanding of coastal evolution drivers. However, interconnections among geological, oceanographical, biological and human key-drivers of coastal change, operatin...

Nowadays volcanic manifestations in the Azores archipelago are represented by several permanent gas emissions that include hydrothermal fumaroles, thermal and cold CO2-rich springs, as well as diffuse degassing areas. Visible manifestations of volcanism are found out in most of the islands and their isotopic imprints give clues both to understand t...

p>Analisa a documentação que compôs o processo judicial movido pelo Deputado Odorico Mendes contra o Ex-presidente do Maranhão Costa Pinto, na Corte do Rio de Janeiro, em 1829. Todo o corpo documental do processo está disponível num livreto que compõe o acervo do Arquivo Nacional do Rio de Janeiro. Com exceção a um ou outro documento, de modo geral...

Here, we present the first detailed study on diffuse CO 2 degassing in the lakes in the Western Group (Corvo and Flores islands) of the Azores archipelago. This research is of interest in order to determine (1) the overall CO 2 emission from such lakes, as volcanic lakes are often underrepresented in the databases of these water bodies, and (2) the...

Estuaries are sensitive to changes in global to regional sea level, to climate-driven variation in rainfall and to fluvial discharge. In this study, we use source and environmentally sensitive proxies together with radiocarbon dating to examine a 7-m-thick sedimentary record from the Sado estuary accumulated throughout the last 3.6 kyr. The lithofa...

Recent work on the central Algarve (south Portugal) has revealed a complex coastal stratigraphic sequence on the Almargem lowland. This sector of the coast is characterized by strong coastline recession, previous studies suggesting that it has retreated over 200 meters over the last 3 centuries. A group of six trenches, making two N-S cross shore p...

A multiproxy study combining paleomagnetic, rock magnetic (magnetic susceptibility; anhysteretic remanent magnetization, ARM; isothermal remanent magnetization, IRM, anisotropy of magnetic susceptibility, AMS) and geochemical (XRF) data was carried out on trench sediments collected in the area of Boca do Rio (Algarve, South Portugal) known to have...

We examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poço do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during...

The fluvio‑estuarine beaches of downtown Lisbon during the Iron Age and Roman Period. In the aim of the Lisbon Stories project several sediment samples, both sediment cores and discrete samples, were recovered in the riverine Lisbon area. The analyses of those sediments will allow rebuilding the palaeoenvironmental evolution of the northern Tagus m...

Platform beaches are small sand accumulations resting on a rocky platform, bounded landward by a cliff or artificial structure and extending seaward not far into the sea. Measuring long-term evolution of platform beaches is essential for an effective and sustainable coastal zone management, but can be challenging because coastline indicators (e.g....

A passagem da depressão Emma (28 de fevereiro-1 de março de 2018) afetou os segmentos litorais da região de Lisboa mais expostos a sul e sudoeste. A agitação marítima associada gerou impactos diferentes em contextos geomorfológicos distintos, que foram caracterizados através da medição da agitação marítima costeira e do alcance horizontal e vertica...

São João da Caparica (Portugal) slow-growing dune system was investigated using field-based GPS and UAV surveying methods. Here, vegetation may preclude straightforward extraction of ground surface data from DSM and low sedimentation rates demand high accuracy. The approach used comprised acquisition of UAV-derived DSM and RGB orthomosaics at fligh...

São apresentados neste trabalho os resultados do estudo de quatro sondagens recolhidas na margem Norte do Tejo. A análise destes sedimentos permite reconstruir a paisagem e compreender a evolução paleoambiental da margem antes da construção dos grandes aterros. A sua interpretação permitiu concluir que: a sedimentação na zona subtidal mais proximal...

The maintenance of salt marsh areas in context of climate change depends on the balance between the salt marsh sedimentation rates and the sea level rise rates. This abstract presents a methodology to quantify the evolution of these areas until the end of the century, considering both parameters. The obtained result allows pointing out that the sal...

In the study of palaeotsunamis it is crucial to decipher the sedimentological record, to derive intensity of past events and to infer different inundation phases. To achieve this goal, it is important to apply high-resolution techniques that allow magnifying intra-deposit details (at a sub-centimetric scale) that otherwise would not be perceived; c...

Study region: Graciosa and Pico islands, Azores, Portugal Study focus: Seawater intrusion is a main driver of groundwater salinization in the Azores archipelago. In order to characterize the associated geochemical processes through major-ion and determination of stable (δ18O; δ2H; δ11B) and radiogenic isotopic ratios (δ87Sr) a total of 46 wells wer...

The resilience of salt marshes to climate change and sea level rise mainly depends on the balance between sedimentation rates and sea level rise rates. A model was developed to forecast how Caldeira de Tróia salt marsh will respond to that global forcing factor. The results indicate that the salt marsh can tolerate the projected rise in sea level f...

Although research focus mostly on high marshes the understanding of sedimentation rates and patterns along the whole intertidal environment is key to improve projection models in different scenarios of sea level rise (SLR). This study presents the results from the analysis of a sediment core collected in a low marsh on the North bank of Caldeira de...

Saltmarshes are essential ecosystems both from an ecological and biological point of view. Furthermore, they constitute an important social niche, providing valuable economic and protection functions. Thus, understanding their rates and patterns of sedimentation is critical for functional management and rehabilitation, especially in an SLR scenario...

Public understanding of coastal dynamics and evolution is of vital importance in supporting the implementation of sustainable coastal management. However, successfully delivering scientific information to the general public is a challenging task. Here we describe " The Beaches of Cascais: past and present " science-based exhibition, aimed at upstre...

Recent and past studies indicate that infectious disease outbreaks often take place after extreme weather events, as microbes, vectors and reservoir animal hosts are able to exploit the disrupted environmental conditions (1). Beaches, due to their proximity to oceans and cities, are often setting of such events affecting microbial communities, both...

Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sour...

Beach sand can harbour pathogenic and opportunistic microorganisms, as well as faecal indicator bacteria that influence directly the bathing water quality. Pathogenic and opportunistic microorganisms often raise concern of exposure during beach related recreational activities. In this work, three different types of sandy beaches (natural basaltic,...

Coastal overwash is one of the most important hazards affecting the coastal zone and therefore has been the focus of several studies related to the establishment of setback lines. However, studies of extreme overwash (EO) events along urban beaches backed by a seawall or structure are scarce, and reveal the difficulties associated with its assessme...

This work presents results of sedimentological and paleoecological analysis performed in EDP1 core taken at the Tagus North margin in Lisbon (Cais do Sodré), where four units were defined. Sedimentation of bottom unit 1 occurred in an estuarine environment, in low energy conditions. Unit 2 corresponds to deposition in a high-energy environment, cha...

The geological record of the 1755 tsunami is widespread along Algarve lowlands but no other unequivocal signature of tsunami inundation was found in onshore sediments deposited since Roman times. This chapter addresses the research undertaken on the documentary and geological evidences of destructive tsunamis in the south-facing Algarve coast of Po...

The Western Massif of the Picos de Europa (43°N – 4‐5°W) includes some of the highest peaks in the Cantabrian Mountains. This massif was heavily glaciated during the Last Glaciation, though the post‐glacial environmental evolution is still poorly understood. Using a geomorphological and sedimentological approach, we have reconstructed the environme...

Tsunamis are highly energetic events that may destructively impact the coast. Resolving the degree of coastal resilience to tsunamis is extremely difficult and sometimes impossible. In part, our understanding is constrained by the limited number of contemporaneous examples and by the high dynamism of coastal systems. In fact, long-term changes of c...

The distribution of Recent and Holocene Cyprideis torosa (Jones, 1850) from brackish estuaries and lagoons of mainland Portugal is presented; older Cenozoic C. torosa are also briefly mentioned. Around 550 specimens were found alive, in Melides lagoon (456) and salt marshes from large estuaries (90). Thousands of empty valves and carapaces, with di...

An assessment of tsunami hazard posed to oceanic volcanic archipelagos in the Central Atlantic (Macaronesia) is here presented. The tsunami risk is generally regarded as low in this region. However, accounts of historical tsunami inundation events and geological evidence of past historical and pre-historical tsunami-related inundations affecting th...

Regional/national-scale information on coastline rates of change and trends is extremely valuable, but these studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but it is essential to conduct an integrated and holistic approach to coastline evolution and hence suppor...

Beach sand can harbour pathogenic and opportunistic microorganisms, as well as faecal indicator bacteria that influence directly the bathing water quality. Pathogenic and opportunistic microorganisms often raise concern of exposure during beach related recreational activities. In this work, three different types of sandy beaches (natural basaltic,...