Publications associées à Evidence of extensive lunar crust formation in impact melt sheets 4,330 Myr ago

A lunar reconnaissance drone for cooperative exploration and high-resolution mapping of extreme locations

Erik Uythoven, Thomas Pfeiffer, Daniel Tataru, David Rodriguez Martinez

An efficient characterization of scientifically significant locations is essential prior to the return of humans to the Moon. The highest resolution imagery acquired from orbit of south-polar shadowed regions and other relevant locations remains, at best, ...

Pergamon-Elsevier Science Ltd2024

Fluid flow through microcracked and fractured granitic reservoirs

Marie Estelle Solange Violay, Michael Heap, Lucille Jocelyne Nadine Carbillet

The permeability of crustal rocks and rock-masses dictates the efficiency of hydrothermal circulation and therefore the productivity of geothermal resources. In this study, we find by monitoring P-wave velocity that thermal microcracking in Lanhélin granit ...

2023

Hot rocks: Constraining the thermal conditions of the Mistastin Lake impact melt deposits using zircon grain microstructures

Cyril Cayron

The production of superheated melt during hypervelocity impact events has been proposed to be a common occurrence on terrestrial planetary bodies. Recent direct evidence of superheated impact melt temperatures exceeding > 2370 degrees C from the Kamestasti ...

ELSEVIER2022

Calibration of ground surface albedo models

Christophe Ballif, Arttu Matias Tuomiranta, Pierre-Jean Alet

The emergence of bifacial photovoltaics as a serious option for large-scale power generation makes the accuracy of the in-situ estimation of ground surface albedo increasingly critical. Recent studies have evaluated the performance of different models but ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Water vapor transport in snowpacks

Mahdi Jafari

This thesis is an in-depth treatment of water vapor transport in snowpacks and its impacts on snow structure. The aim is to better understand this transport process and to lay the basis for a model representation in physics-based multi-layer snow models. O ...

EPFL2022

Annual cycle observations of aerosols capable of ice formation in central Arctic clouds

Julia Schmale, Ivo Fabio Beck

The Arctic is warming faster than anywhere else on Earth, prompting glacial melt, permafrost thaw, and sea ice decline. These severe consequences induce feedbacks that contribute to amplified warming, affecting weather and climate globally. Aerosols and cl ...

Nature Research2022

Investigating Magma Ocean Solidification on Earth Through Laser‐Heated Diamond Anvil Cell Experiments

Marco Cantoni, Cécile Hébert, Philippe Gillet, Farhang Nabiei, James Badro, Charles-Edouard Boukaré

We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid lin ...

2021

A new data set of granitic rock strength values from Yosemite Valley, California: applications to rock fall assessment

To explore connections between rock strength and rock falls, we undertook a comprehensive rock mechanics testing program for six granitic rock types in Yosemite Valley (California, USA) where rock falls are a common geomorphic and sometimes hazardous proce ...

2020

Rock strength properties of granitic rocks in Yosemite Valley, Yosemite National Park, California

Michel Jaboyedoff, Federica Sandrone

Yosemite National Park, located in the central part of California’s Sierra Nevada mountains, is a glacially carved landscape filled with iconic rock formations such as Cathedral Peak, El Capitan, and Half Dome. Igneous rocks, consisting primarily of variat ...

U.S. Geological Survey2020

Version 1 of a sea ice module for the physics-based, detailed, multi-layer SNOWPACK model

Michael Lehning, Nander Wever, Katherine Colby Leonard

Sea ice is an important component of the global climate system. The presence of a snowpack covering sea ice can strongly modify the thermodynamic behavior of the sea ice, due to the low thermal conductivity and high albedo of snow. The snowpack can be stra ...

COPERNICUS GESELLSCHAFT MBH2020

Taking the pulse of volcanic eruptions using plagioclase glomerocrysts

Anders McCarthy, Anders Meibom, Stéphane Laurent Escrig, Pierre Vonlanthen

Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chro ...

ELSEVIER2020

Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows

Stéphane Joost, Solange Catherine Gaillard, Elia Vajana

The transhumance system, which consists in moving animals to high mountain pastures during summer, plays a considerable role in preserving both local biodiversity and traditions, as well as protecting against natural hazard. In cows, particularly, milk pro ...

ROYAL SOC2020

Shock-produced high-pressure (La, Ce, Th)PO4 polymorph revealed by microstructural phase heritage of monazite

Cyril Cayron

The responses of uranium-bearing accessory minerals to shock metamorphism have received growing interest, because under extreme pressure and temperature conditions, these phases can form unique microstructures and/or polymorphs and their radiometric ages c ...

GEOLOGICAL SOC AMER, INC2019

Hypervelocity impact testing on stochastic and structured open porosity cast Al-Si cellular structures for space applications

Andreas Mortensen

A hypervelocity (6.7–7.0 km/s) impact testing campaign was conducted using Ø 2 mm, 95% Al projectiles onto A357 aluminium alloy stochastic foams with 4–5 mm typical pore dimensions, or alternatively diamond cubic periodic structures of cast AlSi12 with a 6 ...

2018

The European mountain cryosphere: a review of its current state, trends, and future challenges

Michael Lehning, Wolf Hendrik Huwald

The mountain cryosphere of mainland Europe is recognized to have important impacts on a range of environmental processes. In this paper, we provide an overview on the current knowledge on snow, glacier, and permafrost processes, as well as their past, curr ...

2018

Cubic zirconia in >2370◦C impact melt records Earth’s hottest crust

Cyril Cayron

Bolide impacts influence primordial evolution of planetary bodies because they can cause instantaneous melting and vaporization of both crust and impactors. Temperatures reached by impact-generated silicate melts are unknown because meteorite impacts are e ...

Elsevier2017

From 2D to 3D Characterization of Materials Subjected to Extreme Pressure and Temperature Conditions

Farhang Nabiei

Planetesimal were the first planetary objects to form in the solar system, which later grew to make the proto-planets. Most of these bodies were differentiated as a result of internal heating. Several differentiated bodies have, then, been accreted followi ...

EPFL2017

Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

Michael Lehning, Nander Wever, Mathias Thierry Pierre Bavay

In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous ...

Copernicus GmbH2017

Chemical Characterisation of Deep Earth Reservoirs

Hélène Marie Piet

Seismic imaging of the internal Earth has emphasized the inhomogeneity of its mantle. This interface layer of nearly 3000 km surrounding the central metallic core conducts heat released from the latter, which played a significant role in shaping the actual ...

EPFL2016

Crustal differentiation in the early solar system: Clues from the unique achondrite Northwest Africa 7325 (NWA 7325)

Philippe Gillet

The unique achondrite NWA 7325 is an unusual olivine gabbro composed chiefly of calcic plagioclase (An(85-93)), diopsidic pyroxene (En(50.1-54.0) Wo(44.8-49.3) Fs(0.6-1.3)), and forsteritic olivine (Fo(97)). It is Al and Mg-rich and Fe and Na-poor and disp ...

Pergamon-Elsevier Science Ltd2015