{
  "abstract": "In June 2026 an earthquake swarm of maximum local magnitude (ML) 3.9, comprising 425 matched-filter detections, occurred in the central Rio Grande rift about 45 km north of Socorro, New Mexico, above the northern margin of the Socorro Magma Body (SMB). This setting makes a magmatic or fluid origin the natural hypothesis. We test this hypothesis against the source physics, comparing the swarm with two decades of local seismicity. The swarm b-value is 0.51, low relative to a regional background near 0.83 that includes two prior swarms in the same region. Stress drops are about twice a regional baseline measured by the same method, with the largest events reaching about 10 MPa. The largest event has a well-resolved normal mechanism with no clear isotropic component, and the smaller events are weakly constrained but broadly consistent with normal faulting. Together, a low b-value, elevated stress drops, and the normal mechanisms place the swarm in the non-magmatic, high-differential-stress regime. We interpret the June 2026 swarm as a reactivation of multiple rift-parallel normal faults within the transverse San Acacia accommodation zone, influenced but not driven by the SMB.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "Christopher Calvelage"
    },
    {
      "name": "Jessica Aerts"
    },
    {
      "name": "Susan Bilek"
    },
    {
      "name": "Urbi Basu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/aet5fgexj44wb.bib",
  "cited_by": 0,
  "doi": "10.31223/x56500",
  "fulltext_url": null,
  "id": "aet5fgexj44wb",
  "issns": [],
  "landing_url": "https://eartharxiv.org/repository/view/15213/",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/legalcode",
  "metadata_licence": null,
  "native_subjects": [
    [
      "bepress",
      "Geophysics and Seismology"
    ],
    [
      "bepress",
      "earthquake swarm"
    ],
    [
      "bepress",
      "socorro magma body"
    ],
    [
      "openalex",
      "1908|earthquake and tectonic studies"
    ]
  ],
  "openalex": "W7214639503",
  "pdf_url": "https://eartharxiv.org/repository/object/15213/download/26379/",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/aet5fgexj44wb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:39Z",
      "native_id": "15213",
      "source": "eartharxiv",
      "url": "https://eartharxiv.org/repository/view/15213/"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "bepress:Geophysics and Seismology",
      "subfield": "geophysics"
    }
  ],
  "title": "The June 2026 Socorro swarm: A reactivation of rift-parallel normal faults above the Socorro Magma Body",
  "title_text": "The June 2026 Socorro swarm: A reactivation of rift-parallel normal faults above the Socorro Magma Body",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:39Z",
  "url": "https://research.draconitic.com/paper/aet5fgexj44wb",
  "venue": "EarthArXiv",
  "versions": []
}