@article{fdi:010090759,
  title = {{A} new portable penetrometer for measuring the viscosity of active lava},
  author = {{H}arris, {M}. {A}. and {K}olzenburg, {S}. and {S}onder, {I}. and {C}hevrel, {M}agdalena {O}ryaelle},
  editor = {},
  language = {{ENG}},
  abstract = {{V}iscosity is a fundamental physical property of lava that dictates style and rate of effusive transport. {S}tudies of lava viscosity have predominantly focused on measuring re-melted rocks in the laboratory. {W}hile these measurements are well-constrained in temperature, shear rate, and oxygen fugacity, they cannot reproduce the complexities of the natural emplacement environment. {F}ield viscosity measurements of active lava are the only way to fully capture lava's properties, but such measurements are scarce, largely due to a lack of easy-to-use, portable, and accurate measurement devices. {T}hus, there is a need for developing suitable field instruments to help bolster the understanding of lava. {H}ere, we present a new penetrometer capable of measuring a material's viscosity under the harsh conditions of natural lava emplacement. {T}his device uses a stainless-steel tube with a semi-spherical tip fixed to a load cell that records axial force when pushed into a material, while simultaneously measuring the penetration depth via a free-moving tube that is pushed backward along the penetration tube. {T}he device is portable (1.5 m long, 5.5 kg in weight) and uses a single-board computer for data acquisition. {T}he penetrometer has an operational range from 2.5 x 10(2) to 2.1 x 10(5) {P}a s and was calibrated for viscosities ranging from 5.0 x 10(2) to 1.6 x 10(5) {P}a s. {I}t was deployed to the 2023 {L}itli-{H}r & uacute;tur eruption in {I}celand. {T}hese field measurements successfully recorded the in situ viscosities of the lava in the range of 1.2 x 10(4)-3.4 x 10(4) {P}a s, showcasing it as an efficient method of measuring natural lava viscosity.},
  keywords = {},
  booktitle = {},
  journal = {{R}eview of {S}cientific {I}nstruments},
  volume = {95},
  numero = {6},
  pages = {065103 [14 ]},
  ISSN = {0034-6748},
  year = {2024},
  DOI = {10.1063/5.0206776},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090759},
}