Stress triggering and the Canterbury earthquake sequence

Sandy Steacy, Abigail Jimenez, Caroline Holden

    Research output: Contribution to journalArticle

    14 Citations (Scopus)

    Abstract

    The Canterbury earthquake sequence, which includes the devastating Christchurch event of 2011 February, has to date led to losses of around 40 billion NZ dollars. The location and severity of the earthquakes was a surprise to most inhabitants as the seismic hazard model was dominated by an expected Mw > 8 earthquake on the Alpine fault and an Mw 7.5 earthquake on the Porters Pass fault, 150 and 80 km to the west of Christchurch. The sequence to date has included an Mw = 7.1 earthquake and 3 Mw ≥ 5.9 events which migrated from west to east. Here we investigate whether the later events are consistent with stress triggering and whether a simple stress map produced shortly after the first earthquake would have accurately indicated the regions where the subsequent activity occurred. We find that 100 per cent of M > 5.5 earthquakes occurred in positive stress areas computed using a slip model for the first event that was available within 10 d of its occurrence. We further find that the stress changes at the starting points of major slip patches of post-Darfield main events are consistent with triggering although this is not always true at the hypocentral locations. Our results suggest that Coulomb stress changes contributed to the evolution of the Canterbury sequence and we note additional areas of increased stress in the Christchurch region and on the Porters Pass fault.
    LanguageEnglish
    Pages1-8
    JournalGeophysical Journal International
    DOIs
    Publication statusPublished - 13 Oct 2013

    Fingerprint

    Earthquakes
    earthquakes
    earthquake
    stress change
    slip
    inhabitants
    seismic hazard
    hazards
    Hazards
    occurrences

    Keywords

    • Earthquake interaction
    • forecasting
    • and prediction
    • earthquake dynamics
    • seismicity and tectonics

    Cite this

    Steacy, Sandy ; Jimenez, Abigail ; Holden, Caroline. / Stress triggering and the Canterbury earthquake sequence. In: Geophysical Journal International. 2013 ; pp. 1-8.
    @article{061f5e66e1844342a1b71910e4da46a8,
    title = "Stress triggering and the Canterbury earthquake sequence",
    abstract = "The Canterbury earthquake sequence, which includes the devastating Christchurch event of 2011 February, has to date led to losses of around 40 billion NZ dollars. The location and severity of the earthquakes was a surprise to most inhabitants as the seismic hazard model was dominated by an expected Mw > 8 earthquake on the Alpine fault and an Mw 7.5 earthquake on the Porters Pass fault, 150 and 80 km to the west of Christchurch. The sequence to date has included an Mw = 7.1 earthquake and 3 Mw ≥ 5.9 events which migrated from west to east. Here we investigate whether the later events are consistent with stress triggering and whether a simple stress map produced shortly after the first earthquake would have accurately indicated the regions where the subsequent activity occurred. We find that 100 per cent of M > 5.5 earthquakes occurred in positive stress areas computed using a slip model for the first event that was available within 10 d of its occurrence. We further find that the stress changes at the starting points of major slip patches of post-Darfield main events are consistent with triggering although this is not always true at the hypocentral locations. Our results suggest that Coulomb stress changes contributed to the evolution of the Canterbury sequence and we note additional areas of increased stress in the Christchurch region and on the Porters Pass fault.",
    keywords = "Earthquake interaction, forecasting, and prediction, earthquake dynamics, seismicity and tectonics",
    author = "Sandy Steacy and Abigail Jimenez and Caroline Holden",
    year = "2013",
    month = "10",
    day = "13",
    doi = "10.1093/gji/ggt380",
    language = "English",
    pages = "1--8",
    journal = "Geophysical Journal International",
    issn = "0956-540X",

    }

    Stress triggering and the Canterbury earthquake sequence. / Steacy, Sandy; Jimenez, Abigail; Holden, Caroline.

    In: Geophysical Journal International, 13.10.2013, p. 1-8.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Stress triggering and the Canterbury earthquake sequence

    AU - Steacy, Sandy

    AU - Jimenez, Abigail

    AU - Holden, Caroline

    PY - 2013/10/13

    Y1 - 2013/10/13

    N2 - The Canterbury earthquake sequence, which includes the devastating Christchurch event of 2011 February, has to date led to losses of around 40 billion NZ dollars. The location and severity of the earthquakes was a surprise to most inhabitants as the seismic hazard model was dominated by an expected Mw > 8 earthquake on the Alpine fault and an Mw 7.5 earthquake on the Porters Pass fault, 150 and 80 km to the west of Christchurch. The sequence to date has included an Mw = 7.1 earthquake and 3 Mw ≥ 5.9 events which migrated from west to east. Here we investigate whether the later events are consistent with stress triggering and whether a simple stress map produced shortly after the first earthquake would have accurately indicated the regions where the subsequent activity occurred. We find that 100 per cent of M > 5.5 earthquakes occurred in positive stress areas computed using a slip model for the first event that was available within 10 d of its occurrence. We further find that the stress changes at the starting points of major slip patches of post-Darfield main events are consistent with triggering although this is not always true at the hypocentral locations. Our results suggest that Coulomb stress changes contributed to the evolution of the Canterbury sequence and we note additional areas of increased stress in the Christchurch region and on the Porters Pass fault.

    AB - The Canterbury earthquake sequence, which includes the devastating Christchurch event of 2011 February, has to date led to losses of around 40 billion NZ dollars. The location and severity of the earthquakes was a surprise to most inhabitants as the seismic hazard model was dominated by an expected Mw > 8 earthquake on the Alpine fault and an Mw 7.5 earthquake on the Porters Pass fault, 150 and 80 km to the west of Christchurch. The sequence to date has included an Mw = 7.1 earthquake and 3 Mw ≥ 5.9 events which migrated from west to east. Here we investigate whether the later events are consistent with stress triggering and whether a simple stress map produced shortly after the first earthquake would have accurately indicated the regions where the subsequent activity occurred. We find that 100 per cent of M > 5.5 earthquakes occurred in positive stress areas computed using a slip model for the first event that was available within 10 d of its occurrence. We further find that the stress changes at the starting points of major slip patches of post-Darfield main events are consistent with triggering although this is not always true at the hypocentral locations. Our results suggest that Coulomb stress changes contributed to the evolution of the Canterbury sequence and we note additional areas of increased stress in the Christchurch region and on the Porters Pass fault.

    KW - Earthquake interaction

    KW - forecasting

    KW - and prediction

    KW - earthquake dynamics

    KW - seismicity and tectonics

    U2 - 10.1093/gji/ggt380

    DO - 10.1093/gji/ggt380

    M3 - Article

    SP - 1

    EP - 8

    JO - Geophysical Journal International

    T2 - Geophysical Journal International

    JF - Geophysical Journal International

    SN - 0956-540X

    ER -