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NEWS

December 2024 ESRFnews

Rocks below the surface of the Earth’s

crust could be far more permeable

than previously thought, according to

measurements taken in the lab and at

the ESRF’s flagship BM18 beamline.

The results bode well for the human

exploitation of geothermal energy,

which relies on being able to pump

water from the crust to the Earth’s

surface.

Conventional geothermal systems

rely on extracting the heat from water

pumped from the upper, brittle regions

of the Earth’s crust. At greater depths,

where drills can just about reach,

there is the promise of hotter water,

and therefore more energy. This is

softer rock, however, and until now

geophysicists had assumed it lacked

the voids and fracture networks that are

necessary for the water to flow through.

“It’s impossible to study these rocks

in situ, as they are too deep, so no

one really knew whether this is true or

not,” says Gabriel Meyer, an author

of the new study, who is based at the

Swiss Federal Institute of Technology

Lausanne (EPFL). “So we decided to

study them in the lab and at the ESRF,

where we could recreate the conditions

of pressure and temperature that take

place in that zone.”

Meyer and his colleagues began

by deforming rocks in the lab, and

measuring their permeability, before

taking them to the BM18 beamline

to study with X-ray tomography.

Based on the data, the ESRF’s Benoit

Cordonnier could model the zone

of the Earth’s crust. The analysis

showed that, despite the softness of

rocks under such high deformation,

the strain can be greater than in

brittle rock – suggesting that water

circulation is in fact possible (Nat.

Commun. 15 7753).

“The results are really encouraging,”

says Meyer.

X-rays hint at new potential

for geothermal energy

Users have taken data on the ID21

nanoscope for the first time, revealing

a potential to trace nanoparticles with

unprecedented speed and precision.

Visiting from the University of

Bordeaux in France, the users have

been familiarising themselves with

the new instrument to pinpoint the

location of iron in neurons for the

study of neurodegenerative diseases

At 150 nm the spatial resolution

of the new ID21 has been paramount

for the success of our experiment

says Asunción Carmona one of the

team In order to find the trace

concentrations of iron we needed

a high photon flux of about one

hundred billion photons per second

which we have now with EBS

The new ID21 nanoscope offers

enhanced capabilities for nanoX

ray fluorescence mapping nano

Xray absorption spectroscopy and

hyperspectral X-ray fluorescence

mapping. Among its improvements

are a higher lateral resolution

down to 100 nm better Xray

fluorescence detection capacities

subppm higher acquisition speed

an improved cryogenic sample

environment and a new graphical

user interface

When affected by neuro

degenerative diseases neurons can

accumulate metals and protein

aggregates says Carmona We want

to know how these metals contribute to

neurodegeneration and the new ID21

nanoscope is the ideal tool for us

Murielle Salomé, engineer and Hiram Castillo-Michel, ID21 scientist, at work on the beamline.

E S R F/ S T E F C A N D É

Nanoscope opens to users

“The spatial resolution of the new

ID21 has been paramount for the

success of our experiment”

E S R F S T E F C A N D É

Benoit Cordonnier at BM18