Ewch i’r prif gynnwys
Dr Ricardo Ramalho

Dr Ricardo Ramalho

Lecturer in GeoEnvironmental Hazards

Email
ramalhor@cardiff.ac.uk
Campuses
Y Prif Adeilad, Plas y Parc, Caerdydd, CF10 3AT
Users
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Trosolwg

I am geologist whose research focuses on the geodynamics and hazards of ocean island volcanoes.

Ocean island volcanoes are some of the most prominent and rapidly-forming structures on Earth, yet their origins are still very enigmatic as they still cannot be explained by conventional plate tectonics. They also feature one of the most dynamic landscapes in our planet, being the source of highly devastating geohazards such as paroxysmal eruptions, giant lateral collapses, and megatsunamis. Research on ocean island volcanoes is thus one of the last frontiers in the comprehension of our Planet’s internal dynamics and is fundamental for countries with sovereignty over volcanic archipelagos, such as the UK.

My central aim is to understand how island volcanoes grow and decay, at different time and spatial scales, and how that evolution reflects the holistic interaction between surface processes and deep earth mechanisms.

My work also focuses on investigating the hazard potential posed by island volcanoes, spanning subjects as diverse as volcanic eruptions (their dynamics, effects and frequency), landslides (trigger mechanisms and effects), tsunamis (generation, propagation and impact), lahars (trigger mechanisms and effects), storms (frequency and impacts), and coastal erosion (as a function of a range of different factors).

My research is therefore very broad, bridging the fields of volcanic geology, plate tectonics & structural geology, geomorphology, stratigraphy, sedimentology, and natural hazards.

My work is very field based (both onshore and offshore), but extends and relies on range of other complementary laboratorial and modelling techniques, making it very interdisciplinary and collaborative in nature.

Keywords:

  • Ocean island volcanoes
  • Geodynamics
  • Hotspots
  • Landscape evolution
  • Landslides
  • Tsunamis
  • Volcanic eruptions

Bywgraffiad

Academic Positions:

2021: Lecturer, Cardiff University
2016: Senior Research Fellow and Invited Lecturer, Instituto Dom Luiz, University of Lisbon
2013: Marie Curie Independent Outgoing Research Fellow, University of Bristol & Lamont-Doherty Earth Observatory of Columbia University
2011: Postdoctoral Research Assistant, Münster University

Honorary/Adjunct Positions:

Honorary Researcher and Invited Lecturer at Instituto Dom Luiz, University of Lisbon (Portugal).
Honorary Senior Research Fellow, School of Earth Sciences, University of Bristol (UK).
Adjunct Associate Research Scientist, Lamont-Doherty Earth Observatory of Columbia University (USA).

Education

2010: PhD Earth Sciences, University of Bristol
2004: MSc Dynamic Geology, University of Lisbon
2001: Lic. (Hons) Geology, University of Lisbon

Awards:

Springer Thesis Award (2011) - one of a few selected outstanding PhD theses from around the world and across the physical sciences in 2011.
Runners-up Best Talk (2007) at the British Geophysical Association Postgraduate Research in Progress Meeting, 2-4 September 2007, Cardiff.

Professional Membership:

2007 – present: Fellow of the Geological Society of London
2008 – present: member of the American Geophysical Union
2011 – present: member of the European Geosciences Union
2012 – present: member of the International Association of Volcanology and Chemistry of Earth's Interior

Cyhoeddiadau

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My research focuses on the geodynamics and hazards of ocean island volcanoes. I generally employ an integrative onshore-offshore approach, combining field observations with geochronology and quantitative analyses to unravel the evolution of ocean island volcanoes and their landscapes, at different time and spatial scales. Crucially, my work increasingly focuses on investigating the hazard potential posed by island volcanoes, under a multitude of perspectives that, beyond focusing on solid Earth processes, also studies events that result from land-ocean-atmosphere interactions in connection with mechanisms of global change. Accordingly, my research activities span a variety of topics, chiefly:

Ocean island evolution, magmatism and volcanic hazard

I am fascinated by how ocean island volcanoes evolve through space and time, as a function of the holistic interaction between internal geodynamics and external factors. I am particularly interested in the evolution of ocean island volcanoes and oceanic hotspots located at stationary or slow-moving plate environments with respect to their melting source (e.g. Cape Verde, Madeira and Canaries), or of those located close to mid-ocean ridges and triple junctions (e.g. Azores).

In these settings my research chiefly focuses on  how competing volcanic and intrusive processes govern island growth, how complex uplift/subsidence histories reflect episodic changes in magmatic system behaviour, and how the lack of surface volcanism does not necessary translates into magmatic quiescence. I am also contributing to research that integrates geological/geodetic/geophysical/remote sensing data to understand active intrusive processes and their surface expression. In terms of island decay, I have been looking at how islands near rifts may be destroyed by transtensional tectonics.

In terms of volcanic hazard, my research focuses on the use of high-resolution bathymetric surveys to the formulation of solid volcanic hazard assessments on volcanic islands, and on the modulation of volcanic hazard at hydraulically-charged ocean island volcanoes, with links to climate variability.

Hazard potential of volcanic landslides and the tsunamis they trigger

Recently, I have shown that a flank collapse at Fogo – one of the most active oceanic volcanoes on Earth – triggered a large tsunami with dire consequences at ~73 ka. This discovery provides another line of evidence that volcanic flank collapses are indeed capable of triggering megatsunamis, addressing a fierce debate over their real hazard potential.

I am currently leading an highly multidisciplinary international research venture to investigate the regional impact of this tsunami, coupled with a detailed investigation of the source, aiming at the incorporation of physical constraints into new, more robust numerical models for the generation, propagation and impact of volcanogenic tsunamis.

Through this research, we hope to answer 3 of the most fundamental questions hampering our scientific understanding of megatsunami hazard: (1) what is the initial magnitude of these waves (in relation to their volume flux)? (2) how fast they dissipate as they propagate into the distance? i.e. are they capable of significant damage across ocean basins? (3) How frequent are these events?

We are also working to establish more solid criteria to identify tsunami deposits on volcanic islands and extract meaningful parameters in event reconstruction. We are also exploring the hazard potential posed by smaller but much more frequent tsunamis triggered by coastal cliff failures, using an integrative high-resolution onshore/offshore approach coupled with numerical modelling. The idea is to use historical examples to calibrate numerical tools for hazard & risk analysis of this type of events.

Coastal evolution, erosion, shelf sediment dynamics, and island biogeography

My work is incredibly multi-disciplinary and includes contributions to the fields of Earth surface processes, environmental hazards, and in particular coastal science. I am particularly interested on how volcanic island coastlines and shelfs evolve as a function of volcanism, mass wasting, erosion, sedimentation and interaction with biological processes.

We are now working to offer more quantitative insights to the subject, namely through the increased use of a combined onshore/offshore approach, linking fieldwork on land with very high-resolution marine geophysics, and by incorporating the latest advances in geomorphological numerical modelling into our analysis.

I also actively collaborate with biologists and palaeontologists in the study of fossil insular marine biotas and on the influence of island ontogeny and glacio-eustatic oscillations in patterns of marine biogeography.

Active Research Projects

  • UNTIeD – UNlocking the megaTsunamI Deadlock: using the near-source impacts to constrain tsunami generation by volcanic flank collapses. (2018–2022, PI).
  • HAZARDOUS - Evaluating HAZARDs related to the formation and development of detrital and lavic “fajãs” in the POrtugUese volcanic archipelagoS. (2021–2024, Co-PI).
  • SIGHT - SeIsmic and Geochemical constraints on the Madeira HoTspot system. (2018–2022, Co-I).

Past Research Projects:

  • MEGAWAVE – Unravelling the hazard potential of tsunamis triggered by volcanic flank collapses. (2016–2021, PI).
  • M155 cruise – The tsunamigenic gravitational flank collapse of Fogo volcano, Cape Verde Islands. (2019, Co-PI).
  • PLATMAR - Development of volcanic island shelves: insights from Sta. Maria Island and implications on hazard assessment, habitat mapping and marine aggregates management. (2016–2020, Co-I & Task Leader).
  • FIRE - Fogo Island volcano: multi disciplinary REsearch on 2014/15 Eruption. (2016–2020, Co-I & Task Leader).
  • ISLAND FREEBOARD – What can island isostasy tell us about hotspot dynamics. (2013-2016, PI).

Supervision

I am interested in supervising PhD students in the areas of:

  • Geo-environmental hazards
  • Volcanology & volcanic geology
  • Geomorphology of volcanic landscapes
  • Oceanic plate geodynamics & hotspots
  • Coastal evolution of rocky shores
  • Island geological/biological co-evolution

Past projects

Postdoc Supervision:

  • Elodie Lebas. Project title: The tsunamigenic gravitational flank collapse of Fogo volcano, Cape Verde Islands. (2019–2020)
  • Stéphanie Dumont. Project title: Magma transfer to the surface at intraplate stratovolcanoes: from a geophysical characterization to a monitoring perspective. (2017–2022)
  • Ana C. Rebelo. Project title: Living on the edge: rhodolith formation on reefless volcanic island shelves. (2017–222)

PhD Student Supervision:

  • Mariana Andrade. PhD in GeologyProject title: Volcanic hazard at hydraulically-charged Ocean Island Volcanoes – the case of Flores Island (Azores). University of Lisbon, 2018–2022.

MSc Student Supervision:

  • Heidi Brice. MSci in Geology. Project title: Landslide hazard at ocean island volcanoes: the case of Tope de Coroa (Santo Antão, Cape Verde Islands). Univeristy of Bristol, 2020–2021.
  • Ana Teves. MSc in Geography. Project title: Historical lava flows from Fogo Volcano: high-resolution mapping and geomorphological analysis. IGOT, 2017-2018.
  • Carlos Melo. MSc in Geology – Project title: Origins and evolution of coastal talus-platforms (fajãs) with lagoon systems. University of Azores, 2014–2016.