PhD Student, Volcanology, David Colby @dj_colby: A Day in the GeoLife Series

David Colby
David Colby at the highest point of Isla Clarion, a remote volcanic island 1100 km west of the Mexican coast. ©2019 David Colby

NAME: David Colby

CURRENT TITLE: PhD Student in physical volcanology

AREA OF EXPERTISE: Physical volcanology; Geochemistry



BSc Physical Geography: University of Hull
MSc Volcanology: University of Bristol
Currently studying towards DPhil: University of Oxford


TWITTER NAME: @dj_colby

What’s your job like?

I am currently studying toward my PhD, researching the eruptive history and magmatic evolution at Corbetti Volcano, Ethiopia. Ethiopia is ranked as having the 5th highest risk to human life from a volcanic source of any country in the world. This is partly due to the lack of understanding about the activity that has occurred at its 59 Holocene volcanos. I am conducting fieldwork, textural, and geochemical analysis to determine the dynamics of eruptions that have occurred at Corbetti volcano, one of the largest calderas in the Main Ethiopian Rift. I will be trying to determine the scale of the activity and how the magmas that caused these eruptions were generated. The type of activity that has occurred at Corbetti has been very varied, despite the composition of the magma remaining roughly consistent over the last 170,000 years, raising lots of interesting questions around controls on eruptive styles and the generation of peralkaline magmas. My project will hope to answer some of these questions and hopefully give a clearer picture of the risk this volcano poses. 

Corbetti Volcano
Corbetti Volcano viewed from across Lake Hawassa, Ethiopia. It’s last major eruption was over 2000 years ago however, now 250,000 people live within 30 km of it. ©2019 David Colby

I also have the opportunity to do lots of outreach in local schools and with different groups that visit the university. It is a great opportunity to share my passion for volcanology and get other people interested in Earth Sciences!

What’s a typical day like?

Every day is different and can be quite varied! I am just finishing my 1st year as a PhD student so most of my time has been devoted to exploring the literature and refining my research questions in conjunction with my supervisors. I am currently preparing for my first field season to Ethiopia in November. I will go to Corbetti and conduct a detailed survey of the eruptive deposits in the caldera and collect samples for analysis to try and understand the different styles of volcanic activity and the risk it might currently pose. Part of this planning involves some preliminary geochemical and textural analysis to determine if the techniques I have chosen to use will yield useful results. This data will inform what sort of samples I need to collect during my time in Ethiopia. I also frequently help with outreach activities within the department and at my college talking to students about volcanology and Earth Sciences and why it is such an awesome subject!

Hiking over the 2015 PDC deposit from Volcan de Colima, Mexico, looking for suitable sample locations. ©2019 David Colby

What’s fun?

I am fascinated with the forensic aspect of volcanology, looking at the products of volcanic eruptions in detail and using that information to reconstruct what happened thousands or even millions of years ago. I am always amazed at how much information you can get from just looking at rocks, their crystal content and chemical composition. All of this information can be used to tell a story of a volcanoes past and what future risk it might pose. 

Sunset over Volcan de Colima, viewed from Nevado de Colima. ©2019 David Colby

I have also been very fortunate to travel to some amazing countries including Italy, Mexico, Guatemala and Ethiopia. It has been a great opportunity to explore different cultures and be exposed to different ways of life. During my time in Mexico, I spent a month helping to map the geology of a remote island (Isla Clarion) 1100 km off the west coast of Mexico. It was quite an isolating month and hard work but a fantastic experience being almost completely detached from the modern world whilst looking at some amazing geology!

Isla Clarion
Marveling at some of the spectacular pyroclastic deposits on Isla Clarion. ©2019 David Colby

What’s challenging?

Organising my time can be quite challenging especially when I’m having to juggle multiple tasks. At times I sometimes focus on the most interesting thing rather than the most important! Other times, when my data yields unexpected results, it can be challenging to figure out why especially as I’m on quite a steep learning curve and no one has looked at this before so no one knows the right answer!

What’s your advice to students?

Always do things that you enjoy and take advantage of any opportunity that presents itself to you even if it is something you hadn’t previously considered. A lot of my best experiences have required me to step outside my comfort zone. It can be scary at first but it is always worth the effort! 

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