The 2011 off the Pacific coast of Tohoku Earthquake: Postseismic Slip Distribution Model (Preliminary)

Postseismic Slip Distribution Model Inferred from GEONET data

Released: Mar. 15, 2011, Updated: Mar. 29, 2013, Japanese version of this page

Postseismic Slip Distribution Model

We constructed a postseismic slip (afterslip) distribution model using surface displacement data observed by the GPS Earth Observation Network System (GEONET) for the 2011 off the Pacific coast of Tohoku Earthquake.
  • Eastward displacements are observed along the Pacific coast from Aomori Prefecture to Chiba Prefecture.
  • The observed postseismic displacement partly includes crustal deformation due to aftershocks.
  • A postseismic slip expands in and around the inferred coseismic slip area. In particular, relative large slips are estimated in the northwest and in the south (off Choshi) of the coseismic slip area.
Table. 1 Postseismic deformation and estimated slip
Perioda Maximum
horizontal
displacement
Estimated slip
(Maximum)
Estimated slip
(southern local
maximum)
Moment
magnitude
(Mw)
2011-03-13 06:00 ~12 cm b ~37 cm ~23 cm 8.03
2011-03-14 03:00 ~15 cm b ~47 cm ~27 cm 8.10
2011-03-15 03:00 ~18 cm b ~55 cm ~32 cm 8.14
2011-03-16 09:00 ~23 cm ~66 cm ~37 cm 8.16
2011-03-18 03:00 ~25 cm ~73 cm ~41 cm 8.19
2011-03-22 03:00 ~29 cm ~87 cm ~47 cm 8.24
2011-03-25 03:00 ~32 cm ~97 cm ~52 cm 8.27
2011-03-31 03:00 ~37 cm ~108 cm ~57 cm 8.31
2011-04-07 03:00 ~41 cm ~123 cm ~61 cm 8.33
2011-04-14 03:00 ~44 cm ~136 cm ~65 cm 8.36
2011-04-21 03:00 ~46 cm b ~150 cm ~69 cm 8.38
2011-04-28 03:00 ~49 cm ~158 cm ~74 cm 8.39
2011-05-05 03:00 ~51 cm ~163 cm ~74 cm 8.42
2011-05-12 03:00 ~53 cm ~172 cm ~77 cm 8.42
2011-05-29 18:00 ~57 cm ~189 cm ~84 cm 8.44
2011-06-13 18:00 ~61 cm ~200 cm ~87 cm 8.46
2011-06-26 18:00 ~63 cm ~204 cm ~89 cm 8.48
2011-07-12 18:00 ~65 cm ~216 cm ~90 cm 8.48
2011-07-27 18:00 ~68 cm ~226 cm ~94 cm 8.50
2011-08-14 18:00 ~70 cm ~238 cm ~99 cm 8.51
2011-08-29 18:00 ~72 cm ~243 cm ~99 cm 8.52
2011-09-27 18:00 ~76 cm ~257 cm ~102 cm 8.53
2011-10-31 18:00 ~79 cm ~270 cm ~104 cm 8.55
2011-11-27 18:00 ~81 cm ~279 cm ~106 cm 8.56
2011-12-25 18:00 ~84 cm ~288 cm ~107 cm 8.57
2012-01-29 18:00 ~86 cm ~298 cm ~110 cm 8.57
2012-02-26 18:00 ~88 cm ~309 cm ~111 cm 8.58
2012-03-26 18:00 ~89 cm ~318 cm ~112 cm 8.59
2012-06-26 18:00 ~96 cm ~344 cm ~118 cm 8.61
2012-09-25 18:00 ~101 cm ~366 cm ~121 cm 8.62
2012-12-26 18:00 ~105 cm ~389 cm ~121 cm 8.64
2013-03-25 18:00 ~109 cm ~408 cm ~124 cm 8.65
a All periods start at 18:00, March 11, 2011 in Japan Standard Time (JST)
b The GPS data at which the maximum displacement was observed in most periods were not available for this period.

Notice:
  • Update of this page is stopped in March, 2013 because a rate of postseismic deformation became small.
  • This is a preliminary result. The analysis result is possibly updated with adding new data.
  • We updated the models before April 4, 2011 with additional GPS data. (Updated on February 3, 2012)

Slip Distribution Model

NEW 20110311 18:00 to 20130325 18:00 JST

Postseismic slip distribution
Postseismic slip distribution[PDF: 106KB]

Fitting between observation and calculation
Fitting between observation and calculation (horizontal)[PDF: 116KB] Fitting between observation and calculation (vertical)[PDF: 119KB]

Comparison between coseismic and postseismic slip distributions
Comparison between coseismic and postseismic slip distributions[PDF: 103KB]

Previous results
 
Period Postseismic
slip distribution
Fitting
(Horizontal comp.)
Fitting
(Vertical comp.)
Postseismic slip distribution and Fitting between observation and calculation
2012-12-26~ PDF: 189KB PDF: 223KB PDF: 229KB
2011-09-27~2012-09-25 PDF: 803KB PDF: 957KB PDF: 979KB
2011-05-05~2011-08-29 PDF: 851KB PDF: 949KB PDF: 971KB
2011-03-25~2011-04-28 PDF: 786KB PDF: 956KB PDF: 979KB
2011-03-13~2011-03-24 PDF: 799KB PDF: 937KB PDF: 957KB
 
Period Coseismic and
postseismic slip
distributions
Coseismic and
postseismic displacements
(Horizontal comp.)
Coseismic and
postseismic displacements
(Vertical comp.)
Comparison between coseismic and postseismic slip distributions / ground displacements
2012-12-26~ PDF: 183KB PDF: 202KB PDF: 199KB
2011-09-27~2012-09-25 PDF: 736KB PDF: 858KB PDF: 840KB
2011-05-05~2011-08-29 PDF: 864KB PDF: 854KB PDF: 837KB
2011-03-25~2011-04-28 PDF: 717KB PDF: 857KB PDF: 839KB
2011-03-13~2011-03-24 PDF: 761KB PDF: 848KB PDF: 835KB

The 2011 off the Pacific coast of Tohoku Earthquake

Date-Time March 11, 2011 14:46 JST
March 11, 2011 05:46 UTC
Hypocenter Location 38.103°N, 142.860°E, Depth: 24 km (JMA, as of March 13, 2011)
38.322°N, 142.369°E, Depth: 22.4 km (USGS, as of March 13, 2011)
Moment Magnitude 9.0 (JMA, as of March 13, 2011)
9.0 (USGS, as of March 13, 2011)

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Contact

HATANAKA Yuki : Director of Division (Crustal Deformation Research Division)
OZAWA Shinzaburo : Chief Researcher (Crustal Deformation Research Division)
NISHIMURA Takuya : Chief Researcher (Crustal Deformation Research Division)
SUITO Hisashi : Cheif Researcher (Crustal Deformation Research Division)
KOBAYASHI Tomokazu : Researcher (Crustal Deformation Research Division)

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