災害 · 小笠原地震小笠原諸島西方の深発地震、暫定マグニチュード7.0執筆 2026年10月26日 12:53 UTC視聴文字起こし0:07An earthquake shook the Ogasawara Islands from four hundred and seventy kilometers0:10underground.0:11Its preliminary magnitude is seven point zero, with shaking measured on Chichujima0:15and Hahajima.0:16The Japan Meteorological Agency said there was no tsunami concern, and no tsunami0:20warnings were issued.0:21What the shaking did to island residents and essential services is still unclear.0:26The earthquake struck west of the Ogasawara Archipelago with its preliminary0:30epicenter offshore.0:31Its estimated depth was approximately four hundred and seventy kilometers.0:34The readings from Chichijima and Hahajima describe the shaking that reached those0:38islands from that deep underground source.0:40The earthquake began at eleven nine Sunday morning, October25,2026 , Japan0:46Time.0:47That origin time marks when the earthquake started.0:49Instruments detected its waves later.0:51The automated system then produced estimates that changed substantially.0:54The magnitude and depth in the event summary are still preliminary.0:58Magnitude seven point zero describes the earthquake size.1:01On Chichijima, Mikazukiyama recorded intensity three, while Nishimachi recorded1:05intensity two.1:06Hajima also recorded intensity three.1:09Each intensity reading describes ground motion at that station.1:12Two stations on the same island registered different intensities.1:15That's why the magnitude alone can't tell residents how strongly their particular1:18location shook.1:19Japan uses ten intensity categories.1:21They run from zero to seven, with lower and upper categories at five and six.1:25The island readings were intensity three and intensity two.1:28Japan switched to automatic instrumental intensity observations in April one1:32thousand nine hundred and ninety-six.1:34Before that, observers assessed shaking through what people felt and what happened1:37around them.1:38Today's readings come from instruments measuring motion at a particular site.1:42An intensity meter measures movement in three directions: two horizontal and one1:46vertical.1:47The calculation filters the signal for earthquake, wave periods, and combines those1:51movements.1:51It then uses an acceleration threshold exceeded for a total of zero point three1:55seconds to derive the published intensity category.1:57Those measurements give a precise account of ground motion where instruments sit.2:01Assessing injuries or the condition of buildings and essential services takes2:05information from the communities themselves.2:06An intensity reading can't supply that assessment.2:09Even when the earthquake's magnitude and depth are known, the earthquake began2:13before instruments logged its waves.2:15Detection came at about eleven ten, followed seven seconds later by the first2:19automated forecast.2:20That forecast estimated magnitude five point nine and a depth of ten kilometers.2:25The preliminary event summary superseded those first estimates with magnitude seven2:29point zero and a depth of approximately four hundred seventy kilometers.2:32Those entries track earthquake detection and early warning forecasts.2:36Tsunami warnings are issued separately.2:38The initial forecast shallow depth therefore shouldn't be carried forward as the2:41depth of this earthquake.2:43A separate calculation gives a moment magnitude of six point five and a centroid2:47depth of four hundred and ninety nine kilometers.2:50The centroid is the calculated center of seismic energy release.2:54It describes a different feature from the preliminary depth where the earthquake2:57began.2:58Japan uses both JMA magnitude and moment magnitude to describe earthquake size.3:03The agency lists seven point zero alongside the separate moment.3:06Magnitude calculation of six point five.3:09Reading those figures together as a downward revision would confuse two different3:12calculations.3:13The event summary continues to label its magnitude seven point zero as preliminary.3:17No tsunami warnings were issued, but serious destruction or casualties haven't been3:21confirmed either.3:22The measured island shaking is the clearest consequence so far.3:26Residents still lack a confirmed assessment of local damage and disruption to3:29essential services.3:31Local officials haven't provided a confirmed picture of injuries, damage, or service3:35disruption.3:35Emergency services haven't provided an event specific account of evacuations or3:39deployments.3:40The no tsunami assessment leaves those questions about the earthquake's effects on3:43land unresolved.記事を読むストーリーの時系列HeyDexショート動画 ↗誰が何を報じたか1社だけが報じた論点9Xinhuaのみが報道An earthquake of magnitude 7.0 struck waters near Japan’s Ogasawara Islands on Sunday.10月25日 2:34 UTCThe Starのみが報道A preliminary magnitude 7.0 earthquake struck waters west of the Ogasawara Archipelago.10月25日 4:13 UTCThe Japan Meteorological Agency said there was no threat of a tsunami.10月25日 4:13 UTCNo tsunami warnings were issued for the earthquake.10月25日 4:13 UTCThe earthquake occurred at about 11:10 a.m. local time on Sunday, Oct. 25.10月25日 4:13 UTCThe earthquake was at a depth of about 470 km.10月25日 4:13 UTCThe earthquake registered seismic intensity 3 on Japan’s seven-level scale on Chichijima.10月25日 4:13 UTCThe earthquake registered seismic intensity 3 on Japan’s seven-level scale on Hahajima.10月25日 4:13 UTCThe reported epicentre was at 28.0 degrees north latitude and 139.9 degrees east…10月25日 4:13 UTC各行は、そのメディアの報道から私たちが記録した主張です。2026年10月25日 15:04 UTC時点で比較。
