{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T20:49:02Z","timestamp":1772830142289,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2023,9,16]],"date-time":"2023-09-16T00:00:00Z","timestamp":1694822400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Technology (MOST)","award":["MOST-111-2111-M-006-003"],"award-info":[{"award-number":["MOST-111-2111-M-006-003"]}]},{"name":"Ministry of Science and Technology (MOST)","award":["NSTC-112-2119-M-006-004"],"award-info":[{"award-number":["NSTC-112-2119-M-006-004"]}]},{"name":"Ministry of Science and Technology (MOST)","award":["MOTC-CWB-112_E-04"],"award-info":[{"award-number":["MOTC-CWB-112_E-04"]}]},{"name":"National Science and Technology Council (NSTC)","award":["MOST-111-2111-M-006-003"],"award-info":[{"award-number":["MOST-111-2111-M-006-003"]}]},{"name":"National Science and Technology Council (NSTC)","award":["NSTC-112-2119-M-006-004"],"award-info":[{"award-number":["NSTC-112-2119-M-006-004"]}]},{"name":"National Science and Technology Council (NSTC)","award":["MOTC-CWB-112_E-04"],"award-info":[{"award-number":["MOTC-CWB-112_E-04"]}]},{"name":"Central Weather Bureau (CWB) of Taiwan to National Cheng Kung University","award":["MOST-111-2111-M-006-003"],"award-info":[{"award-number":["MOST-111-2111-M-006-003"]}]},{"name":"Central Weather Bureau (CWB) of Taiwan to National Cheng Kung University","award":["NSTC-112-2119-M-006-004"],"award-info":[{"award-number":["NSTC-112-2119-M-006-004"]}]},{"name":"Central Weather Bureau (CWB) of Taiwan to National Cheng Kung University","award":["MOTC-CWB-112_E-04"],"award-info":[{"award-number":["MOTC-CWB-112_E-04"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This paper discusses the relationship between the vertical ground motion and ionospheric disturbances before the Kumamoto earthquake on 16 April 2016, in Kyushu, Japan, using the vertical ground motion measured by slant gauges widely distributed in Kyushu, and the NmF2 observed by ionosondes in Japan and another region. We provide evidence that vertical ground motion excites internal gravity waves (IGWs) that disturb changes in the ionospheric plasma density. From the spectral analysis results of the vertical ground motion data, the summation of various period (frequency) components analyzed from the original data of the slant gauge shows a possible correlation with the change of NmF2 before the earthquake. On the other hand, the influence of the geomagnetic disturbance on vertical ground motion seems to exist. However, we cannot confirm that vertical ground motion is influenced by the geomagnetic disturbance (Kp index) and that the earthquake is triggered by the geomagnetic disturbance. There are two conditions for the vertical ground motion to disturb variations in the ionospheric plasma density: (1) The effective vertical ground motion period should be shorter than 5 h. In addition, (2) vertical ground motion should continue to exist so that wave energy can be continuously injected into the atmosphere. A possible mechanism with which to modify the ionosphere is discussed. The results of this study can provide a basis for the future ionospheric precursors of earthquakes by using the vertical ground motion.<\/jats:p>","DOI":"10.3390\/rs15184556","type":"journal-article","created":{"date-parts":[[2023,9,17]],"date-time":"2023-09-17T23:32:27Z","timestamp":1694993547000},"page":"4556","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Driving Source of Change for Ionosphere before Large Earthquake -Vertical Ground Motion-"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7069-2434","authenticated-orcid":false,"given":"Chia-Hung","family":"Chen","sequence":"first","affiliation":[{"name":"Department of Earth Sciences, National Cheng Kung University, Tainan 701002, Taiwan"}]},{"given":"Koichiro","family":"Oyama","sequence":"additional","affiliation":[{"name":"International Research Center for Space and Planetary Environmental Science, Kyushu University, Fukuoka 819-0395, Japan"},{"name":"Ltd. Asia Space Environment Research Consortium, Sagamiharashi 252-0124, Japan"}]},{"given":"Hau-Kun","family":"Jhuang","sequence":"additional","affiliation":[{"name":"Institute of Earth Science, Academia Sinica, Taipei 115962, Taiwan"},{"name":"Department of Geosciences, National Taiwan University, Taipei 106216, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1060-6041","authenticated-orcid":false,"given":"Uma","family":"Das","sequence":"additional","affiliation":[{"name":"Indian Institute of Information Technology Kalyani, Kalyani 741235, India"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,16]]},"reference":[{"key":"ref_1","first-page":"A054304","article-title":"A statistical investigation of pre-earthquake ionospheric anomaly","volume":"111","author":"Liu","year":"2006","journal-title":"J. Geophys. Res."},{"key":"ref_2","first-page":"111","article-title":"Simultaneous ionospheric E- and F-layer perturbations caused by some major earthquakes in India","volume":"50","author":"Singh","year":"2007","journal-title":"Ann. Geophys."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.jseaes.2010.02.012","article-title":"A statistical study of ionospheric earthquake precursors monitored by using equatorial ionization anomaly of GPS TEC in Taiwan during 2001\u20132007","volume":"39","author":"Liu","year":"2010","journal-title":"J. Asian Earth Sci."},{"key":"ref_4","unstructured":"(2014). Earthquake Prediction Studies: Seismo Electromagnetics, TERRAPUB."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1016\/j.jastp.2011.02.020","article-title":"Vertical TEC over seismically active region during low solar activity","volume":"73","author":"Astafyeva","year":"2011","journal-title":"J. Atmos. Sol. Terr. Phys."},{"key":"ref_6","first-page":"69","article-title":"Earthquake time low latitude TEC and model estimated values: Identification on earthquake induced atmospheric dynamics","volume":"27","author":"Devi","year":"2011","journal-title":"Adv. Geosci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1777","DOI":"10.1002\/jgra.50208","article-title":"Ionospheric disturbances of the 2007 Bengkulu and the 2005 Nias earthquakes, Sumatra, observed with a regional GPS network","volume":"118","author":"Mokhamad","year":"2013","journal-title":"J. Geophys. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7","DOI":"10.5194\/nhess-10-7-2010","article-title":"Electron and ion density variations before strong earthquakes (M 6.0) using DEMETER and GPS data","volume":"10","author":"Akhoondzadeh","year":"2010","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"A04319","DOI":"10.1029\/2010JA015948","article-title":"Anomalous Ion Density Latitudinal Distribution as a precursor of large earthquake","volume":"116","author":"Oyama","year":"2011","journal-title":"J. Geophys. Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1016\/j.pce.2006.02.011","article-title":"Examples of unusual ionospheric observations made by the DEMETER satellite over seismic regions","volume":"31","author":"Parrot","year":"2006","journal-title":"Phys. Chem. Earth Parts A\/B\/C"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"671","DOI":"10.5194\/nhess-12-671-2012","article-title":"Ionospheric anomalies associated with the Haiti earthquake of 12 January 2010 observed by DEMETER satellite","volume":"12","author":"Sarkar","year":"2012","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4767","DOI":"10.1002\/2013JA019685","article-title":"Multi-satellite observations of enhancement of equatorial ionization anomaly around Northern Sumatra earthquake of March 2005","volume":"119","author":"Ryu","year":"2014","journal-title":"J. Geophys. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1016\/j.asr.2015.08.030","article-title":"Precursory Equatorial Ionospheric Density Enhancement: Contribution from Mid-latitude Large Earthquakes in the North-East Asian Region","volume":"57","author":"Ryu","year":"2016","journal-title":"Adv. Space Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"A11317","DOI":"10.1029\/2008JA013367","article-title":"Reduction of electron temperature in low latitude ionosphere at 600 km before and after large earthquakes","volume":"113","author":"Oyama","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_15","first-page":"36","article-title":"Study of Anomalous behavior of ionosphere prior to large earthquakes\u2014Present and Future","volume":"208","author":"Oyama","year":"2020","journal-title":"Space Res. Today"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1134\/S0016793215040131","article-title":"Physical bases of the generation of short-term earthquake precursors: A complex model of ionization-induced geophysical processes in the lithosphere-atmosphere-ionosphere-magnetosphere system","volume":"55","author":"Pulinets","year":"2015","journal-title":"Geomagn. Aeron."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1016\/j.pce.2006.02.027","article-title":"Electric currents streaming out of stressed igneous rocks\u2014A step towards understanding pre-earthqauke low frequency EM emissions","volume":"31","author":"Freund","year":"2006","journal-title":"Phys. Chem. Earth Parts A\/B\/C"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3189","DOI":"10.1002\/2013JA019392","article-title":"An improved coupling model for the lithosphere-atmosphere-ionosphere sytem","volume":"119","author":"Kuo","year":"2014","journal-title":"J. Geophys. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/j.asr.2004.12.049","article-title":"The ionosphere effect of atmospheric gravity waves excited prior to strong earthquake","volume":"37","author":"Hegai","year":"2006","journal-title":"Adv. Space Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1134\/S1990793111030109","article-title":"Simulation of Seismo-Ionospheric Effects initiated by internal gravity wave","volume":"5","author":"Klimenko","year":"2011","journal-title":"Russ. J. Phys. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2623","DOI":"10.1016\/j.asr.2018.12.042","article-title":"Precursor effect of March 11 2011 off the coast of Tohoku earthquake on high and low latitude ionosphere and its possible disturbing mechanism","volume":"63","author":"Oyama","year":"2019","journal-title":"Adv. Space Res."},{"key":"ref_22","first-page":"50","article-title":"Modification of low-latitude and equatorial ionosphere before large earthquakes","volume":"40","author":"Depueva","year":"2000","journal-title":"Geomagn. Aeron."},{"key":"ref_23","unstructured":"Sears, F.W., Zemansky, M., and Young, D. (1976). University Physics, Addison-Wesley Publishing Company. [5th ed.]."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1759","DOI":"10.5194\/nhess-11-1759-2011","article-title":"The Neutral Temperature in the Ionospheric Dynamo Region and the Relation with the Ionospheric Density during Wenchuan and Pingtung Earthquakes","volume":"11","author":"Sun","year":"2011","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_25","first-page":"69","article-title":"A note on the correlation of seimo-ionospheric perturbations as deduced from F-net seismic observations","volume":"33","author":"Endo","year":"2013","journal-title":"J. Atmos. Electr."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"XV","DOI":"10.1186\/BF03353076","article-title":"Recent progress of seismic observation network in Japan\u2014Hi-net, F-net, K-net, and KiK-net-","volume":"56","author":"Okada","year":"2004","journal-title":"Earth Planets Space"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"021301","DOI":"10.1063\/1.1854197","article-title":"A density distributed high-sensitivity seismograph network in Japan by National Research Institute for Earth Science and Disaster Prevention","volume":"76","author":"Obara","year":"2005","journal-title":"Rev. Sci. Instrum."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"655","DOI":"10.5047\/eps.2011.05.009","article-title":"Tilt records prior to the 2011 off the coast of Tohoku Earthquake","volume":"63","author":"Hirose","year":"2011","journal-title":"Earth Planets Space"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"14879","DOI":"10.1029\/1999JA900093","article-title":"Altitude dependencies in the solar activity variations of the ionospheric electron density","volume":"104","author":"Su","year":"1999","journal-title":"J. Geophys. Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6666","DOI":"10.1002\/jgra.50576","article-title":"Global empirical model of TEC response to geomagnetic activity","volume":"118","author":"Mukhtarov","year":"2013","journal-title":"J. Geophys. Res."},{"key":"ref_31","first-page":"599","article-title":"Synchronization of Micro seismic variations within a minute range of periods","volume":"41","author":"Sobolev","year":"2005","journal-title":"Izv. Phys. Solid Earth"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"445","DOI":"10.5194\/nhess-11-445-2011","article-title":"Seismicity dynamics and earthquake predictability","volume":"11","author":"Sobolev","year":"2011","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"De Rubeis, V., Czechowski, Z., and Teisseyre, R. (2010). Synchronization and Triggering: From Fracture to Earthquake Processes. Geoplanet: Earth and Planetary Sciences, Springer.","DOI":"10.1007\/978-3-642-12300-9"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1002\/grl.50211","article-title":"Insignificant solar terrestrial triggering of earthquakes","volume":"40","author":"Love","year":"2013","journal-title":"Geophys. Res. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"39","DOI":"10.4236\/ojer.2018.71003","article-title":"Geomagnetic Kp index and earthquakes","volume":"7","author":"Urata","year":"2018","journal-title":"Open J. Earthq. Res."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"11495","DOI":"10.1038\/s41598-020-67860-3","article-title":"On the correlation between solar activity and large earthquakes worldwide","volume":"10","author":"Marchitelli","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_37","first-page":"00137","article-title":"Sudden Fluctuation in Kp Triggers Earthquakes and Tectonics","volume":"7","author":"Mukherjee","year":"2005","journal-title":"Geophys. Res. Abstr."},{"key":"ref_38","unstructured":"Oyama, K.-I., Chen, C.H., Jhuang, H.K., and Das, U. (2023). Daily Variation of NmF2 before Large Earthquakes, Japan Geoscience Union."},{"key":"ref_39","unstructured":"Oyama, K.-I., Chen, C.H., Kakinami, Y., and Uozumi, T. (2022). Intensified Dynamo Electric Field Associated with Large Earthquake, Japan Geoscience Union."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1007\/BF00876083","article-title":"Estimation of the size of earthquake preparation zones","volume":"117","author":"Dobrovolsky","year":"1979","journal-title":"Pure Appl. Geophys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"10051","DOI":"10.1029\/1999JA900028","article-title":"Production of electric filed perturbations by gravity wave winds in the E region suitable for initiating equatorial spread F","volume":"104","author":"Prakash","year":"1999","journal-title":"J. Geophys. Res."},{"key":"ref_42","first-page":"369","article-title":"Different behavior of TEC and NmF2 observed during large geomagnetic storms","volume":"56","author":"Jin","year":"2009","journal-title":"J. Natl. Inst. Inf. Commun. Technol."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/18\/4556\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:52:05Z","timestamp":1760129525000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/18\/4556"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,16]]},"references-count":42,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["rs15184556"],"URL":"https:\/\/doi.org\/10.3390\/rs15184556","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,16]]}}}