Category Archives: Earth Observation

Observations and models of Icelandic eruption lead to new understanding of volcanic systems

In November 2023, a state of emergency was suddenly declared in a fishing town in Iceland, Grindavík, and all residents were rapidly evacuated. In the space of around 6 hours, escalating seismic activity was felt: large cracks and fault movements occurred at the earth’s surface, and homes, businesses and infrastructure were destroyed.

This devastation was caused by huge amounts of magma moving at an unprecedented speed below the surface, which rushed into a crack that opened up below the town. The intrusion that formed was approximately 15-kilometres-long and extended around 1-5 km deep, with widening of up to 8 meters.

The processes and timescales behind the formation of major cracks, or “dikes”, aren’t currently fully understood but the international team of researchers behind a paper published in Science today have revealed new findings that shed some light on how these hazardous events occur.

Using detailed satellite observations alongside seismic measurements and physical modelling, the team of investigators led by University of Iceland and the Icelandic Meteorological Office, found that the magma flow rate under the surface of the earth reached an ultra-rapid and previously unrecorded speed of 7400 cubic meters per second. The study also shows that huge amounts of magma can be forced into cracks due to fracturing in the earth and tectonic stress, without much pressure coming from underlying magma source that feeds it. These findings demonstrate a significant hazard potential for this volcanic system and others with similar features, which can result in large-volume magmatic eruptions on the surface.


COMET Scientist, Professor Andy Hooper, was a key member of the team of investigators:

“Nothing like these rates of magma flow have ever been measured before. Luckily, the magma did not make it to the surface at that time, but this helps us understand how magma-filled cracks that are tens of kilometres long may have formed in the past.”


The events in November were the beginning of the activity in the affected area around Grindavík. Smaller magma intrusions occurred in December 2023 and January 2024, which unfortunately culminated in large eruptions and further devastation in the town, and a new, ongoing eruption started this morning (February 8th 2024).

Publication available here (open access for all for two weeks): https://www.science.org/doi/10.1126/science.adn2838

‘Sensing Volcanoes’ at the Royal Society Summer Science Exhibition

From July 4 – 9 this year, a team from the University of Oxford, University of East Anglia and the University of the West Indies, Seismic Research Centre and Montserrat Volcano Observatory ran a multi-sensory installation as one of nine showcase exhibits at the Royal Society’s summer exhibition. Over six days, thirty volunteers helped to run the installation, manage the enthusiastic crowds of children and adults, and showcase aspects of volcanic and geophysical research.

The exhibit was designed around the ‘Curating Crises’ project [https://curatingcrises.omeka.net] funded by AHRC and NERC, which is exploring historical unrest at Caribbean volcanoes using data sources from archives – including the National Archives, the Royal Society, the British Geological Survey and the Montserrat Public Library.

The tag line for the exhibit was ‘sense, detect, imagine’. The idea was to explore how people living near a volcano might sense unrest; and how the detection of unrest feeds into the imagining, or interpretation, of what is happening underground, and what might happen next. To create sensory elements of the installation we had objects including an early 1900’s gramophone trumpet, with the sounds of bubbling geysers; an ash-covered cord telephone (from the 1990’s) with recorded eye-witness accounts of activity on Montserrat, and some tactile pots carved from scoria, impregnated with a mysterious ‘volcano scent’ that had been created for the exhibition. The highlight of the exhibit was the imaginarium – a ‘light up’ floor, controlled by a raspberry Pi. We ran this in two modes – one to represent the seismicity and movement of magma beneath La Soufrière, St Vincent during the 2021 eruption; and the second to run an interactive game on uncertainty and unrest, where the floor transformed into a map view of an island, which then turns out be a volcano.

The exhibit was busy for the whole of the exhibition, with over 4000 visitors to the building over the final weekend alone. Those who dropped by included Janice Panton, the Government of Montserrat representative; Turner-prize winning artist Veronica Ryan, and Cecil Browne, a Vincentian author. The exhibit is portable (with a van!) and will have another outing at the Oxford Festival of Science and Ideas in October.

Thank you to all of our volunteers, funders, and to the artists and creatives – Output Arts, Ωmega ingredients and Lizzie Ostrom – who helped to turn a 2-page vision statement into a physical exhibit in a little over six months!

https://curatingcrises.omeka.net/exhibits/show/sensing-royal-society/sensing-volcanoes

Written by Professor David Pyle, University of Oxford

Bridie Davies (UEA, now Manchester) checking the sound from the gramophone trumpet.
Stacey Edwards (UWI-SRC) and Jenni Barclay (UEA) checking the pendulum array and smelling stones.
The final stages of the uncertainty game. The volcano on the island has erupted, and places where people have chosen to live (represented by toys) have been affected by ash fallout (purple) or pyroclastic flows (orange).

Harmony: Mission Candidate for the Earth Explorer 10

COMET scientists Professor Juliet Biggs (University of Bristol) and Professor Andy Hooper (University of Leeds) both serve on the Harmony Mission Advisory Group and are delighted to have been chosen to develop the concept further.

On February 18-19, ESA’s Programme Board for Earth Observation (PB-EO) decided on the continuation of the three Earth Explorer (EE) mission candidates towards the next phase in the path to their implementation. The three missions, namely, Daedalus, Hydroterra and Harmony, were selected in 2018 for a Phase-0 feasibility study out of 21 submitted proposals. The PB-EO has made now the unprecedented decision of selecting only one mission for Phase A, namely Harmony, instead of more than one as done in previous EE calls.

The Harmony mission is dedicated to the observation and quantification of small-scale motion and deformation fields at the air-sea interface (winds, waves, surface currents), of solid Earth (tectonic strain and height changes at volcanoes), and in the cryosphere (glacier flows and height changes). In order to achieve the different mission goals, the Harmony mission shall deploy two companion satellites following one of ESA’s Copernicus Sentinel-1 satellites. The companions will be flying in two different formations (see Figure 1): the stereo formation, with one Harmony satellite placed in front and one behind Sentinel-1, in both cases at a distance of about 350 km from it; and the cross-track formation, with both Harmony units flying close to each other (~200-500 m) also at 350 km from Sentinel-1. Each Harmony satellite carries as main payload a receive-only synthetic aperture radar (SAR), which shall acquire the reflected signals transmitted by Sentinel-1 towards the Earth. A multi-view thermal infra-red payload is also included to measure cloud height and cloud motion vectors. The angular diversity provided by the Harmonies in combination with Sentinel-1 will allow the retrieval of deformation measurements of the sea and earth surface with unprecedented accuracy (see Figure 2), while the cross-track configuration will allow the accurate measurement of elevation changes for land-ice and volcanic applications.

 

 

 

 

 

Figure 1: Representation of the (left) stereo and (right) cross-track flying formations for Harmony. The Sentinel-1 satellite is depicted in black color. Sentinel-1 transmits a signal and acquires the backscattered echoes (represented with magenta arrows), while the Harmony satellites receive part of the energy that bounces towards them (represented with the green arrows). Copyright: Harmony Mission Advisory Group.

Dr. Paco López-Dekker from the Delft University of Technology and principal investigator of the Harmony mission, comments “It is very exciting that our multi static-SAR concept, which combines many ideas that were matured during my years at HR, has made it to this final stage. During Phase-0 we have drafted a beautiful and elegant mission concept promising an unprecedented view at Earth System processes. Now we have the responsibility to look at it from all sides and be sure that it will work. Challenging and fun.”

Professor Juliet Biggs from the University of Bristol and member of Harmony’s Mission Advisory Group at ESA adds “The Harmony mission is remarkable in that it promises new scientific discoveries across an astonishing breadth of topics: from the gradual motion of tectonic plates to small-scale processes on the ocean surface. I’m delighted that we have been selected to develop the concept further and that Harmony is one step closer to becoming a reality”

Dr. Pau Prats, from the German Aerospace Centre, DLR and member of Harmony’s Mission Advisory Group at ESA, is convinced of the benefits a mission like Harmony will bring to the community: “The unique configuration of the Harmony satellites in combination with Sentinel-1 will allow us to literally add a new dimension to SAR observations, a fact that will foster SAR technology and its applications during the next two decades.”

Figure 2: Coloured areas show regions straining at greater than 10 nanostrain per year (the threshold above which 95% of earthquake fatalities occur). Blue regions are those that have a small component of north-south strain and can be imaged by Sentinel-1 alone. Red regions indicate the extra area that will be constrained by Harmony. From Harmony Report for Assessment. 2020.  

So, what’s next? Even though Harmony is currently the only EE-10 mission candidate it does not mean it will be implemented. The industry and science teams have one and a half years of hard work ahead to demonstrate the mission has reached the technological and scientific level of maturity required to enter into the next phase, that will ultimately result in the launch of the Harmony satellites by the end of this decade.

Announcement can be found on ESA website: https://www.esa.int/Applications/Observing_the_Earth/ESA_moves_forward_with_Harmony

Title figure for the Harmony mission. Copyright: ESA.

 

COMET commentary on satellite InSAR – Nature Communications

How satellite InSAR has grown from opportunistic science to routine monitoring over the last decade

COMET Deputy Director (Volcanoes), Prof. Juliet Biggs, and COMET Director, Prof. Tim Wright, have written a commentary on satellite InSAR for the 10 year anniversary of
Nature Communications out in print! Read the article here.

Fig. 1: Measuring surface movement with InSAR.
An orbiting satellite sends a coherent radar signal to the surface and measures the backscattered radiation. The phase difference (position in the wave cycle) between the signals returning at two different times (time 1 in black and time 2 in red) can be used to estimate ground movement caused by a range of mechanisms. https://www.nature.com/articles/s41467-020-17587-6/figures/1