{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,19]],"date-time":"2025-12-19T15:45:12Z","timestamp":1766159112377,"version":"3.37.3"},"reference-count":34,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2023,2,25]],"date-time":"2023-02-25T00:00:00Z","timestamp":1677283200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2023,2,25]],"date-time":"2023-02-25T00:00:00Z","timestamp":1677283200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020"],"award-info":[{"award-number":["PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020","PTDC\/CTA-GEF\/6674\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005765","name":"Universidade de Lisboa","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100005765","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Geo-Mar Lett"],"published-print":{"date-parts":[[2023,3]]},"abstract":"<jats:title>Abstract\n<\/jats:title><jats:p>This work presents evidence of seasonal and inter-annual variations of the earthquake occurrence rate in the Azores Triple Junction, on the Mid-Atlantic Ridge (MAR). Annual cycles in microearthquakes are relatively common in intraplate continental regions affected by large hydrological loads, but this is the first time that earthquake seasonality is recognized near mid-ocean ridges. First, we benchmark the methodology by matching the published results of earthquake seasonality in the intraplate New Madrid Seismic Zone (USA). Next, we analyze the Azores earthquake catalogue, from 2008 to 2018, separately for oceanic and island regions. The results demonstrate that the seasonal modulation of the seismicity rate is only observed in the ocean, especially in the vicinity of the triple junction, with more earthquakes occurring during the summer months from May to August. Monte Carlo simulations show that the probability of observing such seasonality by chance is less than 1% for the magnitude band from 3.3 to 4.5, well above the detection threshold and magnitude of completeness of the seismic catalogue. The methodology includes a Jack-Knife approach, which shows that the oceanic seasonality is not the consequence of abnormal or extreme events. Although we speculate about possible earthquake triggering processes, it remains a challenge to definitely establish the mechanism responsible for the observed earthquake seasonal modulation in the Azores.<\/jats:p>","DOI":"10.1007\/s00367-023-00744-3","type":"journal-article","created":{"date-parts":[[2023,2,25]],"date-time":"2023-02-25T10:02:47Z","timestamp":1677319367000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Evidence of earthquake seasonality in the Azores Triple Junction"],"prefix":"10.1007","volume":"43","author":[{"given":"Ana L.","family":"Lordi","sequence":"first","affiliation":[]},{"given":"Maria C.","family":"Neves","sequence":"additional","affiliation":[]},{"given":"Susana","family":"Cust\u00f3dio","sequence":"additional","affiliation":[]},{"given":"St\u00e9phanie","family":"Dumont","sequence":"additional","affiliation":[]}],"member":"297","published-online":{"date-parts":[[2023,2,25]]},"reference":[{"key":"744_CR1","doi-asserted-by":"publisher","unstructured":"Bollinger L, Perrier F, Avouac JP et al (2007) Seasonal modulation of seismicity in the Himalaya of Nepal. Geophys Res Lett 34. https:\/\/doi.org\/10.1029\/2006GL029192","DOI":"10.1029\/2006GL029192"},{"key":"744_CR2","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1016\/j.tecto.2007.01.008","volume":"435","author":"JF Borges","year":"2007","unstructured":"Borges JF, Bezzeghoud M, Buforn E, Pro C, Fitas A (2007) The 1980, 1997 and 1998 Azores earthquakes and some seismo-tectonic implications. Tectonophysics 435:37\u201354. https:\/\/doi.org\/10.1016\/j.tecto.2007.01.008","journal-title":"Tectonophysics"},{"key":"744_CR3","unstructured":"CERI. New Madrid Earthquake Catalog (Centre for Earthquake Research and Information, Memphis, TN, USA). https:\/\/www.memphis.edu\/ceri\/seismic\/index.php. Accessed 01 July 2022"},{"key":"744_CR4","doi-asserted-by":"publisher","unstructured":"CMEMS. Global ocean gridded L4 sea surface heights and derived variables reprocessed (1993-ongoing). https:\/\/doi.org\/10.48670\/moi-00148","DOI":"10.48670\/moi-00148"},{"key":"744_CR5","doi-asserted-by":"publisher","unstructured":"Craig TJ, Chanard K, Calais E (2017) Hydrologically-driven crustal stresses and seismicity in the New Madrid Seismic Zone. Nature Communications 8:. https:\/\/doi.org\/10.1038\/s41467-017-01696-w","DOI":"10.1038\/s41467-017-01696-w"},{"key":"744_CR6","doi-asserted-by":"publisher","first-page":"70","DOI":"10.1016\/j.tecto.2016.03.013","volume":"676","author":"S Cust\u00f3dio","year":"2016","unstructured":"Cust\u00f3dio S, Lima V, Vales D et al (2016) Imaging active faulting in a region of distributed deformation from the joint clustering of focal mechanisms and hypocentres: application to the Azores-western Mediterranean region. Tectonophysics 676:70\u201389. https:\/\/doi.org\/10.1016\/j.tecto.2016.03.013","journal-title":"Tectonophysics"},{"key":"744_CR7","doi-asserted-by":"publisher","unstructured":"Dickinson JE, Hanson RT, Predmore SK (2014) HydroClimATe\u2014hydrologic and climatic analysis toolkit: U.S. Geological Survey Techniques and Methods 4\u2013A9, 49 p. https:\/\/doi.org\/10.3133\/tm4a9","DOI":"10.3133\/tm4a9"},{"key":"744_CR8","doi-asserted-by":"publisher","unstructured":"ECCO Consortium, Fukumori I, Wang O, Fenty I, Forget G, Heimbach P, Ponte RM (2021) ECCO Ocean Bottom Pressure - Monthly Mean 0.5 Degree (Version 4 Release 4). Ver.V4r4. PO.DAAC, CA, USA. https:\/\/doi.org\/10.5067\/ECG5M-OBP44","DOI":"10.5067\/ECG5M-OBP44"},{"key":"744_CR9","doi-asserted-by":"publisher","first-page":"2800","DOI":"10.1002\/ggge.20179","volume":"14","author":"I Grevemeyer","year":"2013","unstructured":"Grevemeyer I, Reston TJ, MoelleR S (2013) Buoyancy and localizing properties of continental mantle lithosphere: insights from thermomechanical models of the eastern Gulf of Aden. Geochem Geophys Geosyst 14:2800\u20132817. https:\/\/doi.org\/10.1002\/ggge.20179","journal-title":"Geochem Geophys Geosyst"},{"key":"744_CR10","doi-asserted-by":"publisher","first-page":"252","DOI":"10.1016\/j.jhydrol.2003.10.006","volume":"287","author":"RT Hanson","year":"2004","unstructured":"Hanson RT, Newhouse MW, Dettinger MD (2004) A methodology to asess relations between climatic variability and variations in hydrologic time series in the southwestern United States. J Hydrol 287:252\u2013269. https:\/\/doi.org\/10.1016\/j.jhydrol.2003.10.006","journal-title":"J Hydrol"},{"key":"744_CR11","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1016\/S0012-821X(02)01148-2","volume":"207","author":"K Heki","year":"2003","unstructured":"Heki K (2003) Snow load and seasonal variation of earthquake occurrence in Japan. Earth Planet Sci Lett 207:159\u2013164. https:\/\/doi.org\/10.1016\/S0012-821X(02)01148-2","journal-title":"Earth Planet Sci Lett"},{"key":"744_CR12","doi-asserted-by":"publisher","first-page":"1615","DOI":"10.1002\/2017JB015288","volume":"123","author":"G Horning","year":"2018","unstructured":"Horning G, Sohn RA, Canales JP, Dunn RA (2018) Local seismicity of the Rainbow Massif on the Mid-Atlantic Ridge. Journal of Geophysical Research: Solid Earth 123:1615\u20131630. https:\/\/doi.org\/10.1002\/2017JB015288","journal-title":"Journal of Geophysical Research: Solid Earth"},{"key":"744_CR13","unstructured":"Instituto Portugu\u00eas Do Mar E Da Atmosfera, I.P (2022). Normais climatol\u00f3gicas. https:\/\/www.ipma.pt\/pt\/oclima\/normais.clima\/. Accessed 01 Nov\u00a02022"},{"key":"744_CR14","unstructured":"Instituto Portugu\u00eas Do Mar E Da Atmosfera, I.P (2006). Portuguese national\nseismic network [Data set]. International Federation of Digital Seismograph\nNetworks. doi:10.7914\/SN\/PM. Accessed 01 July 2022"},{"key":"744_CR15","doi-asserted-by":"publisher","first-page":"10,605","DOI":"10.1002\/2017JB014778","volume":"122","author":"CW Johnson","year":"2017","unstructured":"Johnson CW, Fu Y, B\u00fcrgmann R (2017) Stress models of the annual hydrospheric, atmospheric, thermal, and tidal loading cycles on California faults: perturbation of background stress and changes in seismicity. Journal of Geophysical Research: Solid Earth 122:10,605-10,625. https:\/\/doi.org\/10.1002\/2017JB014778","journal-title":"Journal of Geophysical Research: Solid Earth"},{"key":"744_CR16","doi-asserted-by":"publisher","first-page":"e2021JB022251","DOI":"10.1029\/2021JB022251","volume":"126","author":"K Leptokaropoulos","year":"2021","unstructured":"Leptokaropoulos K, Harmon N, Hicks SP et al (2021) Tidal triggering of microseismicity at the equatorial Mid-Atlantic Ridge, inferred from the PI-LAB experiment. Journal of Geophysical Research: Solid Earth 126:e2021JB022251. https:\/\/doi.org\/10.1029\/2021JB022251","journal-title":"Journal of Geophysical Research: Solid Earth"},{"key":"744_CR17","doi-asserted-by":"publisher","first-page":"141","DOI":"10.1023\/A:1004505401547","volume":"20","author":"N Louren\u00e7o","year":"1998","unstructured":"Louren\u00e7o N, Miranda JM, Luis JF et al (1998) Morpho-tectonic analysis of the Azores Volcanic Plateau from a new bathymetric compilation of the area. Mar Geophys Res 20:141\u2013156. https:\/\/doi.org\/10.1023\/A:1004505401547","journal-title":"Mar Geophys Res"},{"key":"744_CR18","doi-asserted-by":"publisher","first-page":"10","DOI":"10.1016\/j.jvolgeores.2006.03.010","volume":"156","author":"JF Luis","year":"2006","unstructured":"Luis JF, Neves MC (2006) The isostatic compensation of the Azores Plateau: a 3D admittance and coherence analysis. J Volcanol Geoth Res 156:10\u201322. https:\/\/doi.org\/10.1016\/j.jvolgeores.2006.03.010","journal-title":"J Volcanol Geoth Res"},{"key":"744_CR19","doi-asserted-by":"crossref","unstructured":"Madeira J, Brum da Silveira A, Hip\u00f3lito A, Carmo R (2015) Active tectonics in the central and eastern Azores islands along the Eurasia-Nubia boundary: a review. In: Geological Society Memoir. Geological Society of London, pp 15\u201332.","DOI":"10.1144\/M44.3"},{"key":"744_CR20","doi-asserted-by":"publisher","first-page":"231","DOI":"10.1016\/j.jvolgeores.2009.01.015","volume":"181","author":"F Martini","year":"2009","unstructured":"Martini F, Bean CJ, Saccorotti G et al (2009) Seasonal cycles of seismic velocity variations detected using coda wave interferometry at Fogo volcano, S\u00e3o Miguel, Azores, during 2003\u20132004. J Volcanol Geoth Res 181:231\u2013246. https:\/\/doi.org\/10.1016\/j.jvolgeores.2009.01.015","journal-title":"J Volcanol Geoth Res"},{"key":"744_CR21","doi-asserted-by":"publisher","first-page":"275","DOI":"10.1007\/s10950-007-9052-4","volume":"11","author":"L Matias","year":"2007","unstructured":"Matias L, Dias NA, Morais I et al (2007) The 9th of July 1998 Faial Island (Azores, North Atlantic) seismic sequence. J Seismolog 11:275\u2013298. https:\/\/doi.org\/10.1007\/s10950-007-9052-4","journal-title":"J Seismolog"},{"key":"744_CR22","doi-asserted-by":"publisher","first-page":"376","DOI":"10.1016\/j.tecto.2013.09.016","volume":"608","author":"MC Neves","year":"2013","unstructured":"Neves MC, Miranda JM, Luis JF (2013) The role of lithospheric processes on the development of linear volcanic ridges in the Azores. Tectonophysics 608:376\u2013388. https:\/\/doi.org\/10.1016\/j.tecto.2013.09.016","journal-title":"Tectonophysics"},{"key":"744_CR23","doi-asserted-by":"publisher","unstructured":"Reasenberg P (1985) Second-order moment of central California seismicity, 1969 1982. J Geophys Res 90:5479\u20135495. https:\/\/doi.org\/10.1029\/jb090ib07p05479","DOI":"10.1029\/jb090ib07p05479"},{"key":"744_CR24","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/s41467-019-10605-2","volume":"10","author":"CH Scholz","year":"2019","unstructured":"Scholz CH, Tan YJ, Albino F (2019) The mechanism of tidal triggering of earthquakes at mid-ocean ridges. Nat Commun 10:1\u20137. https:\/\/doi.org\/10.1038\/s41467-019-10605-2","journal-title":"Nat Commun"},{"key":"744_CR25","doi-asserted-by":"publisher","unstructured":"Stroup DF, Bohnenstiehl DR, Tolstoy M et al (2007) Pulse of the seafloor: tidal triggering of microearthquakes at 9\u00b050\u2032N East Pacific Rise. Geophys Res Lett 34. https:\/\/doi.org\/10.1029\/2007GL030088","DOI":"10.1029\/2007GL030088"},{"key":"744_CR26","doi-asserted-by":"publisher","unstructured":"Stroup DF, Tolstoy M, Crone TJ et al (2009) Systematic along-axis tidal triggering of microearthquakes observed at 9\u00b050\u2032N East Pacific Rise. Geophys Res Lett 36:. https:\/\/doi.org\/10.1029\/2009GL039493","DOI":"10.1029\/2009GL039493"},{"key":"744_CR27","doi-asserted-by":"publisher","first-page":"1825","DOI":"10.1002\/2017GL076497","volume":"45","author":"YJ Tan","year":"2018","unstructured":"Tan YJ, Tolstoy M, Waldhauser F, Bohnenstiehl DWR (2018) Tidal triggering of microearthquakes over an eruption cycle at 9\u00b050\u2019N East Pacific Rise. Geophys Res Lett 45:1825\u20131831. https:\/\/doi.org\/10.1002\/2017GL076497","journal-title":"Geophys Res Lett"},{"key":"744_CR28","doi-asserted-by":"publisher","unstructured":"Tanaka S, Ohtake M, Sato H (2002) Spatio-temporal variation of the tidal triggering effect on earthquake occurrence associated with the 1982 South Tonga earthquake of Mw 7.5. Geophysical Research Letters 29:3\u20131\u20133\u20134. https:\/\/doi.org\/10.1029\/2002gl015386","DOI":"10.1029\/2002gl015386"},{"key":"744_CR29","doi-asserted-by":"publisher","first-page":"503","DOI":"10.1130\/0091-7613(2002)030<0503:BOTSTC>2.0.CO;2","volume":"30","author":"M Tolstoy","year":"2002","unstructured":"Tolstoy M, Vernon FL, Orcutt JA, Wyatt FK (2002) Breathing of the seafloor: tidal correlations of seismicity at Axial volcano. Geology 30:503\u2013506","journal-title":"Geology"},{"key":"744_CR30","doi-asserted-by":"crossref","unstructured":"Vautard R, Yiou P, Ghil M (1992) Singular-spectrum analysis: a toolkit for short, noisy chaotic signals. Physica D-nonlinear Phenomena - PHYSICA D 58:95\u2013126","DOI":"10.1016\/0167-2789(92)90103-T"},{"key":"744_CR31","doi-asserted-by":"publisher","first-page":"374","DOI":"10.1785\/gssrl.72.3.373","volume":"72","author":"S Wiemer","year":"2001","unstructured":"Wiemer S (2001) A software package to analyze seismicity: ZMAP. Seismol Res Lett 72:374\u2013383","journal-title":"Seismol Res Lett"},{"key":"744_CR32","doi-asserted-by":"publisher","unstructured":"Wiese DN, Yuan, D-N, Boening C, Landerer FW, Watkins MM (2018) JPL GRACE Mascon Ocean, Ice, and Hydrology Equivalent Water Height Release 06 Coastal Resolution Improvement (CRI) Filtered Version 1.0. Ver. 1.0. PO.DAAC, CA, USA. https:\/\/doi.org\/10.5067\/TEMSC-7453MJC6.","DOI":"10.5067\/TEMSC-7453MJC6"},{"key":"744_CR33","doi-asserted-by":"publisher","first-page":"3999","DOI":"10.1029\/2001GL013370","volume":"28","author":"WSD Wilcock","year":"2001","unstructured":"Wilcock WSD (2001) Tidal triggering of microearthquakes on the Juan de Fuca ridge. Geophys Res Lett 28:3999\u20134002. https:\/\/doi.org\/10.1029\/2001GL013370","journal-title":"Geophys Res Lett"},{"key":"744_CR34","doi-asserted-by":"publisher","first-page":"1055","DOI":"10.1111\/j.1365-246X.2009.04319.x","volume":"179","author":"WSD Wilcock","year":"2009","unstructured":"Wilcock WSD (2009) Tidal triggering of earthquakes in the Northeast Pacific Ocean. Geophys J Int 179:1055\u20131070. https:\/\/doi.org\/10.1111\/j.1365-246X.2009.04319.x","journal-title":"Geophys J Int"}],"container-title":["Geo-Marine Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00367-023-00744-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s00367-023-00744-3\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00367-023-00744-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,3,10]],"date-time":"2023-03-10T11:12:26Z","timestamp":1678446746000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s00367-023-00744-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,25]]},"references-count":34,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2023,3]]}},"alternative-id":["744"],"URL":"https:\/\/doi.org\/10.1007\/s00367-023-00744-3","relation":{},"ISSN":["0276-0460","1432-1157"],"issn-type":[{"type":"print","value":"0276-0460"},{"type":"electronic","value":"1432-1157"}],"subject":[],"published":{"date-parts":[[2023,2,25]]},"assertion":[{"value":"22 June 2022","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"11 January 2023","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"25 February 2023","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}},{"value":"Not applicable.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"Not applicable.","order":5,"name":"Ethics","group":{"name":"EthicsHeading","label":"Research involving human participants and\/or animals"}},{"value":"The authors declare no competing interests.","order":6,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}}],"article-number":"6"}}