What Controls Recurrent Growth & Collapse Cycles of Large Oceanic Volcanoes - The Case of Tope De Coroa, Cape Verde

The aim of this PhD project is to investigate the factors that lead and control the recurrent cycles of growth and destruction, on a small spatial scale, of prominent ocean island volcanoes.

In particular, the project will seek to provide key insights to the following scientific questions: (a) what structural aspects control the spatial occurrence and recurrence of gravitational flank collapses in these settings? (b) what mechanisms lead to the post-collapse rapid volcanic growth on top of collapse scars? (c) are flank collapses preceded - or accompanied - by paroxysmal explosive eruptions? (d) can we identify a predictable pattern in growth and collapse cycles and their timings, i.e. can we develop tools to forecast the likelihood of future catastrophic events based on their structure, state of flank instability, and gravitational potential?

To answer these questions the student will use Tope de Coroa volcano as a case study.

The student will, accordingly, contribute to the detailed reconstruction of the geological history of the Tope de volcano and the timing of its key formational events using a myriad of tools - such as field observations, Ar-Ar geochronology, volcano-stratigraphic and tephro-stratigraphic correlations (e.g. using geochemical tools), and remote sensing - with significant scope for adaptation of the research programme to suit the student's interests.

A gravimetric survey will also be undertaken to investigate the internal architecture of the region where the volcano is located and the possible causal relationship between gravitational instability and intrusive activity along the island's main structural rift zones, also opening the possibility of exploring more numerical approaches if the student so wishes.

The project will then involve a comparison with the state of knowledge of other volcanic systems, and the drawing of wider implications.

In summary, the project will thus include both a field, instrumental, remote-sensing, and laboratorial component, spanning the disciplines of volcano stratigraphy, structural geology, geophysics, remote-sensing, petrology & geochemistry, and geohazards.