3 persons killed due to the magnitude 6.6 aftershock (Eastern Honshu, Japan)

UPDATE 12/04 - 11:59 UTC : FDMA Report 9 - gives 3 dead, 3 seriously injured and 7 slightly injured persons.

UPDATE 12/04 - 06:23 UTC : It has to be said that the official death toll of this aftershock (based on FDMA reports) stands at 3. The 4th fatality was reported by state network NHK.

UPDATE 12/04 - 00:35 UTC : A 4th person has been reported killed after the 6.6 aftershock of Monday afternoon (local time)

UPDATE 23:51 UTC : We remind our readers that since we started this article, 2 very strong aftershocks have occurred in Chiba prefecture and Nagano Prefecture. Reports on these quakes can be followed here.

UPDATE 23:50 UTC : We will continue to report on this aftershock if we receive more information on this  earthquake

UPDATE 22:06 UTC : We are sad to tell you that compared to our earlier updates, 2 3 other people have been confirmed killed in this 6.6 aftershock.  Although the damage was limited, a mudslide has buried an unspecified  number of houses in Ryugasaki.
3 other people were seriously injured and 1 person remains missing.

UPDATE 19:46 UTC : At the moment there is not much more to report on this quake. People are sleeping which is nice for once, so FDMA and the prefectures have been quiet for the last few hours 🙂 Repeating, that Japan has been comparatively lucky with this earthquake. It is never nice to report on a CATDAT Red earthquake, but we thought this one would be much worse.
Our hearts go out to the family and friends of the 16 year old girl killed in this earthquake in the city of Ryugasaki and also a speedy recovery to the 5 injured in the cities and towns of Kitaibaraki (1), Bando (1), Ushiku (2) and Tsukuba (1).

UPDATE 16:06 UTC : This CBS video is the kind of Tv reporting we like. The right data and some added value news.  The report was aired before that authorities reported the first fatality.

UPDATE 14:06 UTC : Unfortunately we have to report our readers that local authorities said that 1 person was killed by the 6.6 aftershock

UPDATE 12:59 UTC : This is the full damage list as reported by the Fire Department of Japan (Official Emergency service of Japan) at 8 PM local time (at the time we write this, this information is about 3 hours old and a new version will be published soon) :
As a synopsis, we can conclude that this extremely strong aftershock will make more damage and probably will injure tens of people.  Follow our reporting also the coming hours if you have loved ones living or working in these areas.

Fukushima: During dispatch fire investigation vehicle fire in the town Asakawa → 1
Many regional fire department 119 in the local jurisdiction Sukagawa
extinguish fire and gas leak occurred in 3 Iwaki
extinguished the fire from the gas tank of liquefied natural chemicals in plants
cliff collapse occurred in Iwaki City, gets into the car (waiting confirmation number) economic rescue (no injuries)
Destroyed three buildings collapsing due to the cliff house in the city of Iwaki (unknown number of people injured)
Ibaraki Prefecture: 1 gas leak and locked elevator
Two injured in Kitaibaraki City
1 person injured in Ibaraki Seinan
Facilities at Kashima seaside industrial complex : no damage
Tochigi: One person injured in Shioya (minor injury)
Chiba: Ichihara City facilities at the complex, no damage
Kanagawa Prefecture: One injured in Hiratsuka

Nuclear Power Plants
External power is lost by the Fukushima Daiichi Nuclear Power Station, Unit 1 and Unit 2 and Unit 3 coolant pump stops. Shopuld be OK in the meantime.
Tokai Power Station on the second, no damage

UPDATE 12:47 UTC : This is the full list of JMA intensities for the 6.6 magnitude aftershock (this article alone) :
Intensity 6 lower

Fukushima: Iwaki City, Village Nakajima, town Hurudono
Ibaraki Prefecture: City Hokota
Intensity 5 upper
Fukushima Prefecture: Shirakawa, Sukagawa city, town Kagamiishi, Tenei villages, towns Tanagura, Hirata villages, towns Asakawa
Ibaraki Prefecture: Hitachi City, City Joso, Takahagi, Kitaibaraki City, Kasumigaura, Jade City
Tochigi Prefecture: Nasu Town
Intensity 5 lower
Miyagi Prefecture: Iwanuma town Zao Town Wakuya
Yamagata Prefecture: City Kamiyama, Yamabe city, town Zhongshan city Shirataka
Fukushima Prefecture: Koriyama City, City Nihonmatsu, Tamura City, Date City, Motomiya City, Town Nishiaidu ,  Teen town, village Yukawa Yanaizuchō, Aizu Misato Village, Saigo Izumizaki village, town Yabuki, Yamatsuri town, village Samekawa, Ishikawa-cho, Tamagawa Village, Ono town, city Naraha, Futabachō
Ibaraki Prefecture: Mito City, Tsuchiura, Ishioka, Kasama, Tsukuba, Hitachinaka City, Hitati Omiya City, Naka City, Bando, Inashiki City, Future City, Tsukuba Mirai City, Ibaraki city, town Zyou Sato, Daigo, Ami Town
Tochigi Prefecture: Utsunomiya City, Otawara City, Shimono, Haga
Saitama Prefecture: Kasukabe
Niigata Prefecture: Aga Noiti

UPDATE 12:34 UTC : The location of the epicenter of the latest 5.9 magnitude aftershock is luckily in a wilderness area and NOT below a city. Click here to see the map

UPDATE 12:24 UTC : The epicenter of the latest M 5.9 aftershock is centered in Ibaraki-Ken Hokubu

UPDATE 12:18 UTC : JMA Japan has again another magnitude value than USGS, M 5.9 at a depth of 10 km and as earlier reported a intensity of 5- on the 0 to 7 JMA scale.

UPDATE 12:10 UTC : The current aftershocks are VERY DANGEROUS as they occur below land and still have a high intensity (felt experience)

UPDATE 12:04 UTC : Powerful 5.7 aftershock 20 minutes ago resulting in a 5- intensity in Fukushima-ken Nakadori. A 5- intensity is a serious shaking.

UPDATE 11:33 UTC : Ibaraki prefecture intermediate earthquake damage report
* Casualties: 6 injured
* Property damage:  None
* Nuclear Facilities: No problems Toukai Power Station II
* Train: JR whole line postponed
* Power outages : 695 houses in Koga, 337 houses in Takahagi

UPDATE 11:13 UTC : Last official and reliable available information dates from 2 hours 30 minutes ago. At 19:30 local time, there was only mentioning of injured people, NO fatalities so far.
We expect a more reliable update soon.

UPDATE 11:09 UTC : It is currently after dark in Japan (22:09 or 9:09 PM) which will make the work of the Self Defense troops and the Fire Department a lot more difficult.

UPDATE 10:55 UTC : Again FUKUSHIMA prefecture (where some of the coastal Nuclear Plants are located) is among the prefectures which are hit the hardest. TEPCO will certainly release information updates on the ongoing situation in the Daiichi plant.

UPDATE 10:54 UTC : Strongest intensity values :
6-    Fukushima-ken Nakadori, Fukushima-ken Hamadori, Ibaraki-ken Nambu
5+    Ibaraki-ken Hokubu, Tochigi-ken Hokubu

UPDATE 10:45 UTC : The max. JMA intensity for this aftershock is 6- (on a scale of 0 to 7), which makes this aftershock of a lesser intensity than some other aftershocks. This intensity is in line with the recalculated 6.6 magnitude. The early reports were mentioning a 7.0 which would have given at least a 6+ intensity.

UPDATE 10:38 UTC : Latest USGS theoretical calculations on damage and casualties
Red alert level for economic losses. Extensive damage is probable and the disaster is likely widespread. Estimated economic losses are less than 1% of GDP of Japan. Past events with this alert level have required a national or international level response. Yellow alert level for shaking-related fatalities. Some casualties are possible.
74% chance of economic losses between $100 million and $10 billion.
59% chance of 10-100 deaths
34% chance of 100-1000 deaths.
This calculation is based on the decreased magnitude (6.6 instead of 7.1)

UPDATE 10:32 UTC : The aftershock shook buildings and briefly forced Tokyo's main international airport to close both of its runways.

UPDATE 10:30 UTC : The initial 7.1 magnitude has been brought back to a still extremely strong 6.6 magnitude (USGS data, confirmed by EMSC). The initial depth was also recalculated to a super shallow 10 km making the locations in the immediate vicinity of the epicenter a high risk environment.

UPDATE 10:04 UTC : Power outages
The earthquake in the Tohoku region caused 220000 Households in Iwaki City with power outage. On the other hand, in Tohoku Electric Power, the information is that the operation of thermal power plants has stopped. Meanwhile, TEPCO said a momentary power outage occurred in the northeastern part of Ibaraki Prefecture, but it is now restored.

UPDATE 09:48 UTC : The area of today's mainshock (in fact an aftershock),  is currently shaken by many aftershocks, almost all of them in the magnitude 5 range (nat damaging unless for very unstable constructions)

UPDATE 09:34 UTC : The tsunami warning was called during approx. 1 hour. It must be seen as a precaution as the epicenter was located below the island of Honshu (one of the main island of Japan)

UPDATE 09:32 UTC : Tsunami warning cancelled
At around 16:05 pm yesterday, there was a severe earthquake shaking intensity 6 lower observed in Fukushima and Ibaraki Prefecture. Japan Meteorological Agency in this earthquake, a tsunami warning along the coast of Ibaraki, Miyagi and Fukushima, issued a tsunami warning along the coast of Chiba Prefecture And then the tsunami was not observed, the minute 5:06 pm to clear all alerts and warnings.

UPDATE 09:16 UTC - According to METI's Nuclear and Industrial Safety Agency, is that the injection of an external power supply which was enabled No. 3 was stopped from Unit 1 of Fukushima Daiichi Nuclear Power Station. The injection  was stopped at 4:05 pm.

UPDATE 09:06 UTC - According to fire department Iwaki, we observed weak intensity 6, 3 for notification of a fire in a housing and before 6 pm today, that it has received was one report of a landslide.
Casualties are unknown.
According to the police is that landslides have occurred in the town of Iwaki City Watanabe. Whether people are involved should understand that, and police rushed to confirm. According to the police, lights and traffic signal lights go out in a wide range of Iwaki.
This confirms that there is damage from this earthquake, but we can expect the initial reports to rise significantly.

10.04.2011 - 09.00 UTC - GDACS provides a great service for showing what is in the affected region -

Potentially affected critical infrastructure:

  • Nuclear plants: (62km), FUKUSHIMA-DAINI (52km), KASHIWAZAKI KARIWA (198km), ONAGAWA (179km), TOKAI (51km)
  • Hydrodams: Tadami (132km)
  • Airports: Kisarazu (184km), Yokohama (188km), Katsner Aaf (196km), Tokyo Haneda International (174km), Shimoshizu (149km), Chofu (175km), Tachikawa (179km), Yokota Afb (179km), Tokyo Narita International (132km), Shimofusa (140km), Iruma (168km), Ryugasaki South (124km), Ryugasaki (119km), Honda (150km), Chiba-ken (130km), (109km), Hyakuri (86km), Onishi (134km), Shimo Kolzumi (138km), Suzumenomiya (91km), Utsunomiya (88km), Otawara (61km), Fukushima (44km), Niigata (184km), Sendai (137km), Kasuminome (148km), Matsushima (171km), Junmachi (169km), Ojojibara (178km)
  • Ports: Kisarazu (185km), Neghisi (195km), Yokohama (189km), Kawasaki (177km), Goi (164km), Chiba (156km), Anegasaki (156km), Katunan Ko (153km), Ogasawara (161km), Tokyo (159km), Choshi (131km), Kashima (113km), Hitachi (47km), Onahama (17km), Soma (104km), Aikawa (183km), Niigata (185km), Niigata-higashi (179km), Shiogama (159km), Ishinomaki (175km), Onagawa (181km)

10.04.2011 - 08.58 UTC - According to the office Hukuzima TEPCO. The external power supply is cut off that is used to inject water into the reactor of Unit 2 and the No. 1 nuclear power plant Fukushima Daiichi earthquake.  Shortly after 5 pm yesterday, today water injection in the state that it has stopped, the future is that the switch to the fire pump. In addition, the Unit No. 4 is that it has issued an order to evacuate the workers were outside. The value of monitoring posts measuring amount of radiation to surrounding Fukushima Daiichi nuclear power plant so far is that it does not change. (reported from NHK)


10.04.2011 - 08.56 UTC -Ibaraki Prefecture will be heavily affected. It has already 75,000 partially damaged buildings counted from the initial M9.0 earthquake, and can expect many of these to collapse.

10.04.2011 - 08.55 UTC - This is predicted to be much more damaging than the M7.1 aftershock from late last week.

10.04.2011 - 08.54 UTC - This earthquake has been classed as CATDAT Red.

10.04.2011 - 08.52 UTC - Japan has issued a tsunami alert, and evacuated workers at Japan's stricken nuclear plant.

News sources said the alert was for a 0.74m tsunami. So this is not that large, and will be mostly due to local effects.

10.04.2011 - 08.47 UTC - Much damage expected close to the epicenter which is currently shown as onshore.

JMA currently has M7.1 as the magnitude also, with a very shallow hypocenter. Let us remind viewers, that shallow earthquakes can cause much larger damage, given the lesser distance needed.

From GDACS, the earthquake happened in Japan , Tohoku Province (population: 9984608). , 5km from the city of Ueda. The nearest populated places are Ono-Yasashi (18km), Kezuruki-Yashiki (17km), Wakaguri (17km), Isohara (14km), Kisara (14km), Shuku (14km), Shimo-Kimida (17km), Ohata (14km), Yokokawa (14km), Uchino (11km), Onida (16km), Okaneda (13km), Yunami (9km), Koshigoe (9km), Hirakata (9km), Okami (16km), Yanagizawa (13km), Mizunuma (8km), Tonobatake (19km), Terashita (7km), Saimaru (7km), Idekura (4km), Kubota (5km), Ogawa (2km), Yama-Ogawa (12km), Nagura (16km), Obama (12km), Minami-Odaira (6km), Hatta (3km), Soeno (8km), Onahama (15km), Futta (8km), Otsu (6km), Tabyuto (4km), Kami-Yamoda (6km), Tanebe (11km), Nijibu (8km), Akagona (15km), Kuroda (6km), Sumiyoshi (16km), Kami-Kamato (10km), Taki (8km), Sekifune (15km), Kaidomari (12km), Shionohira (10km), Shimo-Yata (20km), Mabarado (14km), Iritono (13km), Tsuzura (18km), Nita (16km), Daibara (19km).

JMA Agency - all rights reserved

There is obviously the danger to the nuclear power plants, with this being so close to the plants.

Intensity 6 lower Fukushima Nakadori Fukushima Hamadori

Southern Ibaraki Prefecture

Intensity 5 upper Northern Ibaraki Prefecture Northern Tochigi Prefecture

Intensity 5 lower Northern Miyagi Miyagi-ken Nanbu

Murayama, Yamagata Prefecture Yamagata Okitama Aizu, Fukushima Prefecture

Southern Tochigi Southern Saitama Niigata Kaetsu

Damage can be expected in these locations primarily.

USGS is coming through with the following details.

Data hereunder has been adapted at the recalculated new numbers.

Most important Earthquake Data:
Magnitude : 6.6
UTC Time : Monday, April 11, 2011 at 08:16:13 UTC
Local time at epicenter : Monday, April 11, 2011 at 05:16:13 PM at epicenter
Depth (Hypocenter) : 10 km
Send an "earthquake experience report" for this earthquake
Geo-location(s) :
36 km (22 miles) W of Iwaki, Honshu, Japan
44 km (27 miles) SSE of Koriyama, Honshu, Japan

Links to important maps
USGS Did You Feel It Map
Google satellite map of the earthquake area
3-dimensional view of the earthquake area (USGS epicenter location)
USGS historic earthquakes map
USGS Seismic hazard map
USGS Impact on Population map
USGS Shaking map

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  1. Michael Dennis Stagg says

    Was not that yesterday ? Much the same as the previous tsunami warning issued by the earthquake expert authorities which only a few heeded and many preceded. Keep an eye on this it gets more active just as Italian landslides, China and Philippine slips, wash, flood, subsidence, rising rock Peru, more jammed estuary sites ... NZ was struck opffshore Wellington too. USA west from Bering to Baja is endelessly shattered by small vibrations, eventually the stuctures come apart in moderate shock.