{
  "abstract": "A C T Crystallisation-driven volatile exsolution (second boiling) is widely invoked to pressurise shallow magma reservoirs, yet its ability to generate eruption-triggering overpressure and detectable ground deformation is poorly quantified. We couple phase equilibria with thermal and viscoelastic models of sill-like intrusions to map pressure evolution and geodetic detectability of second boiling. Thermodynamic calculations for basaltic and rhyolitic magmas from Askja (Iceland) and Puyehue-Cordón Caulle (Chile) are embedded in conductive thermal models for thin (20 m) and thick (200 m) sills at 2-4 km depth, and the resulting volume changes and magma compressibility are propagated into pressurisation histories and volume-change rates. Hydrous magmatic sills can develop overpressures of 20-30 MPa on timescales of months to centuries, depending on initial sill size and crustal parameters, whereas relatively dry basalt undergoes cyclic behaviour with contraction followed by modest re-pressurisation. For a given composition and depth, thin and thick sills attain similar overpressures but differ by an order of magnitude in volume-change rate. Only small, volatile-rich sills exceed typical InSAR resolution thresholds. In felsic crust, viscoelastic relaxation further dampens overpressure and surface deformation, consistent with globally observed reduced deformation at arc volcanoes. Our results define a regime of \"stealth\" pressurisation in shallow hydrous reservoirs, in which magma emplaced centuries earlier may accumulate eruption-scale overpressure with little or no unrest detectable by short temporal baseline geodetic monitoring. This mechanism can help explain unexpected explosive eruptions with little precursory deformation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "Gregor Weber"
    },
    {
      "name": "Juliet Biggs"
    },
    {
      "name": "Alain Burgisser"
    },
    {
      "name": "Catherine Annen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/67wt8zermsr5w.bib",
  "cited_by": 0,
  "doi": "10.1016/j.epsl.2026.120391",
  "fulltext_url": null,
  "id": "67wt8zermsr5w",
  "issns": [
    "0012-821X"
  ],
  "landing_url": "https://hal.science/hal-05858076v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.sdu.stu"
    ],
    [
      "hal",
      "2.sdu.stu.vo"
    ],
    [
      "openalex",
      "1908|earthquake and tectonic studies"
    ]
  ],
  "openalex": "W7221173840",
  "pdf_url": "https://hal.science/hal-05858076/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/67wt8zermsr5w.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T12:20:54Z",
      "native_id": "hal-05858076",
      "source": "hal",
      "url": "https://hal.science/hal-05858076v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "hal:2.sdu.stu.vo",
      "subfield": "geology-geochemistry"
    }
  ],
  "title": "Stealth pressurisation of boiling magma limits geodetic detectability of volcanic eruptions",
  "title_text": "Stealth pressurisation of boiling magma limits geodetic detectability of volcanic eruptions",
  "type": "peer-reviewed",
  "updated_at": "2026-11-10T12:20:54Z",
  "url": "https://research.draconitic.com/paper/67wt8zermsr5w",
  "venue": "Earth and Planetary Science Letters",
  "versions": []
}