Icelandic insights
Due to scant monitoring, volcanic activity in Iceland’s interior is poorly understood compared to neighbouring parts. Jennifer Jenkins aims to change that by leading a seismic deployment across the island’s heart
Fagradalsfjall volcano, Reykjanes Peninsula, Iceland, in 2021. While this region is well monitored by the country’s seismic network, Iceland’s ice-covered Central Highlands are not – something that Jenny and her colleagues aim to rectify during an expedition in summer 2024
The spectacular eruptions on the Reykjanes Peninsula, which have been ongoing since 2021, have once again turned the world’s attention to Iceland, land of fire and ice. As one of the most volcanically active regions on the planet, much of the country, particularly in the south and north, is closely monitored by the nation’s seismic network. However, vast, mostly ice-covered swathes of the island’s heart are sparely instrumented and understudied. Central Iceland may be comparatively less active but, as Jenny Jenkins, Assistant Professor at Durham University explains, that doesn’t mean there is nothing going on.
“There are several active volcanoes covered by glaciers with associated geothermal systems, and persistent seismicity has been observed over the past several decades. But because of the limited number of nearby seismic instruments, very little is known about the causes of this seismicity (and there may well be a lot more of it than we are currently capable of recording), or the internal structure or hazard level of the volcanoes in this area.”
This summer, Jenny, together with collaborators at the University of Iceland and Iceland Geosurvey, will lead an expedition to deploy seismometers through the remote Central Icelandic Highlands.
“Our new network will allow us to record small local earthquakes currently below the level of detection, locate them with a high degree of accuracy, and analyse their source characteristics to work out what’s causing them. Is it movement of magma, or geothermal fluids and gases, or the accommodation of tectonic motion across the boundary of a proposed microplate?
“I love looking at complex noisy data and gradually finding ways of pulling out signals and detailed information”
“We will also use recordings of continuous seismic background noise to image the subsurface – by identifying regions where seismic waves travel particularly fast or slow, we can learn about the internal structure of volcanoes in the area. Finally, recording of distant global earthquakes will allow us to image the large-scale crustal structure, to explore how it changes as you move gradually away from the centre of the Icelandic hotspot (which is potentially caused by a mantle plume), and consider what this structure tells us about how crustal formation processes vary with changing melt sources.”
“Our new network will allow us to record small local earthquakes currently below the level of detection,” explains Jennifer Jenkins
This will be Jenny’s first opportunity to lead a seismic deployment. Come summer, she will also be seven months pregnant, which she says, “adds another layer of complications to the planning!” – complications that will be eased by her great fi eld team and supportive collaborators.
Order from chaos
Beyond Iceland, Jenny’s observationally focused work uses seismic data to unravel goings on within the entire planet – from the formation and deformation of Earth’s crust to the temperature, compositional variation and structure of the mantle.
“I find it amazing that thousands of recordings of tiny ground motions at Earth’s surface can provide us with insights into the deep structures and processes within our planet. I love looking at complex noisy data and gradually finding ways of pulling out signals and detailed information from what at first just looks like a big mess.”
Despite some assumptions that new evidence may largely just support already well-understood processes, Jenny finds that new data frequently counter expectations.
“What usually follows is me trying to work out if I have just made some mistake, or done my analysis wrong. Eventually, I have to accept that the data show that things aren’t exactly how we thought they were. Once you start looking for alternate explanations that do fit your observations, that’s when things get really exciting. Maybe my interpretations aren’t correct and someone else one day will come up with a better explanation – if and when that happens, I look forward to seeing what ideas they come up with.”
Inspiring others
On discovering geophysics at undergraduate level, Jenny realised that her passions for physics, maths and geology could be combined: “I love this rather niche subject that lets me apply physics and maths to better understand the planet we live on.” Jenny shares her enthusiasm for geophysics by teaching undergraduate courses at Durham University, courses which include fieldwork and geophysical data collection in local areas, giving the students opportunities to work with local people on real problems such as, “Is there a permeable area of the subsurface beneath this embankment that could explain flooding problems? Is there really a Roman road running through this fi eld as suggested on historic maps?”
Some of the students’ dissertation projects have led Jenny in unexpected research directions: “An initial student survey opened up surprising new collaborative opportunities with the Engineering Department. I am currently working with colleagues to adapt standard geophysical electrical imaging methods to monitor water infiltration and damage in heritage masonry bridges!”
Despite the wide applicability and critical importance of geophysical methods and knowledge, as with many subfields of geoscience, geophysics is currently suffering recruitment problems in the UK.
“It’s an interesting and important subject that can provide students with key skills and knowledge needed to address the Sustainable Development Goals and implement a green energy transition, and employers are keen to hire geophysics graduates. Yet our courses have consistently low or declining numbers.
“With the British Geophysical Association, I’m leading a project to promote geophysics in high school. We’re starting by collecting data from representatives throughout the educational pipeline (teachers, high school students, undergraduates, graduates, and geophysics companies), in an attempt to answer questions such as: What are the awareness levels of geophysics in high school? Is the subject viewed as too specialised? Are students put off by the thought of fieldwork? Are they worried it’s too hard or too easy? Are they worried it won’t lead to a good career? Do they think that geophysicists only work in the oil industry, with the oft-associated negative connotations? By learning the answers to these questions, we can begin to address the issues.”
As the current Equality, Diversity and Inclusivity (EDI) Officer for the British Geophysical Association, and as a member of Durham’s Earth sciences departmental committee for EDI, Jenny also devotes significant energy to collecting and analysing data on student welfare, and designing policies to help those who need support. With these efforts, Jenny hopes to build the appeal of and inclusivity within geophysics, and ultimately to share the subject she so loves with many more people.
Jennifer Jenkins is an Assistant Professor of Earth Science at Durham University, UK, and the 2024 recipient of the Geological Society’s Wollaston Fund.
Interview by Amy Whitchurch
