Triangulation scale error caused by the 1894 Shonai earthquake: a possible cause of erroneous interpretation of seismic potential along the Japan Trench
Abstract
Keywords
Triangulation Crustal strain GPS The 2011 Tohoku-oki earthquake The 1894 Shonai earthquake Shionohara baseline Baseline surveyIntroduction
The 2011 Mw9.0 Tohoku-oki earthquake was an unexpected giant earthquake for most seismologists. Matsuzawa (2011) summarized five reasons why seismologists believed that there would be no potential for a giant M9 earthquake along the Japan Trench: (1) The subducting Pacific plate is old and cold. Based on comparative subductology (Uyeda and Kanamori 1979), interplate coupling was considered small; (2) triangulation data for the last 100 years showed no E–W contraction; (3) there existed a high activity of small to middle sized earthquakes that were supposed to release tectonic strain at weakly coupled plate interface; (4) major earthquakes along the Japan trench were followed by large afterslip (e.g. Kawasaki et al. 2001), which suggested interplate coupling was not strong; (5) many small repeating earthquakes have been occurring along the Japan Trench (Igarashi et al. 2003), which indicates fault creep on the plate interface. Among these reasons, the lack of E–W contraction during the last 100 years was the most important since an E–W contraction is direct evidence of tectonic stress build-up associated with the subduction of the Pacific plate and interplate coupling. In this paper, we argue this understanding was probably inaccurate and try to explain why such misunderstanding occurred.
The Japanese triangulation network was established in the late nineteenth century to provide a reference for precise surveying and mapping of the whole country. Since Japan is located in a tectonically active region, conspicuous crustal deformation occurs associated with large earthquakes and volcanic activities. In addition, significant crustal deformation also occurs during interseismic periods, reflecting tectonic stress build-up due to plate motions. Resurveying of the triangulation network has provided us with important knowledge about crustal movements, and many studies have been conducted by utilizing those data (e.g. Muto 1932; Ando 1971; Harada and Kassai 1971; Nakane 1973a, b; Sato 1973; Fujii et al. 1986; Tada 1986; Hashimoto 1990; Hashimoto and Jackson 1993; Ishikawa and Hashimoto 1999).
Geodetic data in the Tohoku area. a GPS velocity during 1996–2000. Reference point is Oogata (950241) along the Japan Sea coast of the southwestern end of the plot. Green lines show the active fault traces. Gray velocity arrows are removed for the strain rate calculation because of local disturbances. b Strain rate distribution calculated from GPS velocity using the method of Shen et al. (1996). c Strain distribution from repeated triangulation (1883/1901—1977/94)
The occurrence of the 2011 Tohoku-oki earthquake revealed that our evaluation about the seismic moment budget was wrong, implying a possible defect in the interpretation of the triangulation records. However, there has been no explanation why such misunderstanding occurred. In the following, we demonstrate that an unintentional error in the original triangulation in the l890′s has brought a significant bias in the reference system over a wide area in northeast Japan and caused misinterpretation of the crustal deformation which led to the underestimation of accumulated slip deficit along the Japan Trench.
Strain rate of northeast Japan
Figure 1 compares the strain rate distribution in northeast Japan based on GPS data during 1996–2000 and that based on triangulation for 100 years (Ishikawa et al. 1998). E–W contraction is evident all over the Tohoku area in the GPS result. On the other hand, E–W contraction is not evident in the triangulation result over the twentieth century and significant N–S extension is identified. Similar pattern was reported by Hashimoto (1990) and Ishikawa and Hashimoto (1999) who corrected coseismic offsets due to major earthquakes to estimate interseismic crustal strain rate.
Discrepancies between the two results need some explanation. One possible explanation is that E–W contraction was a short-term feature that would be released by aseismic fault slips either as afterslips following large earthquakes or as unknown slow slip events during interseismic periods. Kawasaki et al. (2001) demonstrated that aseismic fault slips following M7 class earthquakes along the Japan trench contribute equally to or even larger than the coseismic slips. Plate boundary slips can release interseismic E–W contraction. But this interpretation cannot explain how to reproduce N–S extension identified in the triangulation.
First-order triangulation network in Japan except for Hokkaido. Dense networks with gray circular background indicate the locations of baselines. The network shown by red color was measured until October 1894 while the blue network was measured after October 1894
Schematic diagram showing an apparent N–S extension as a sum of a true E–W contraction signal plus an isotropic scale error
Such a significant discrepancy between crustal strain patterns is found only in the Tohoku area. This indicates, if the baseline survey caused this discrepancy, the baseline in the Tohoku area should be responsible for the error. As is shown in Fig. 2, there are only two baselines in the Tohoku area, one is the Shionohara baseline in the Yamagata Prefecture in middle Tohoku, and the other is the Tsurunokotai baseline in the Aomori Prefecture. Since the discrepancy between the GPS and triangulation strain rate pattern is significant in middle-southern Tohoku, we considered the measurement of the Shionohara baseline might have a problem.
The Shionohara baseline
The Shionohara baseline (5129.5872 m) is composed of the two first-order triangulation control points at its eastern and western ends. This is the only original baseline in Japan whose both control points still exist at their original locations today, connected by a straight road for surveying. The baseline was constructed and measured from May to July in 1894. Then, surveys of a dense triangulation network around the Shionohara baseline was conducted from August to October in 1894. To the south of the Shionohara baseline, the Pacific coastal side was surveyed before 1894, while the Japan Sea coastal side was surveyed later. The whole network to the north was surveyed afterward (Fig. 2). The original survey as well as calculation records of the Shionohara baseline is preserved in the archives of the Geospatial Information Authority of Japan (former Geographical Survey Institute, the successor of the Military Land Survey that conducted the original triangulation survey). We checked the original calculation log for the Shionohara baseline. Detailed survey record is shown in Table 1. The overview of the baseline survey is summarized as follows.
Detailed survey record of the Shionohara baseline
Segment | Survey 1 | Survey 2 | Survey 3 | Survey 4 | Average (m) | S.D. (mm) | ||||
---|---|---|---|---|---|---|---|---|---|---|
Date and time | Length (m) | Date and time | Length (m) | Date and time | Length (m) | Date and time | Length (m) | |||
1 | 5/31 5:00–7:57 | 389.9987 | 6/16 16:03–19:39 | 389.9981 | 6/19 5:23–8:20 | 389.9992 | 7/3 16:35–18:50 | 389.9985 | 389.9987 | 0.4 |
2 | 6/16 5:01–7:48 | 398.4272 | 5/31 15:40–18:06 | 398.4268 | 7/3 4:55–7:09 | 398.4271 | 6/20 14:55–17:35 | 398.4269 | 398.4270 | 0.2 |
3 | 6/1 4:57–8:27 | 490.9707 | 6/14 15:40–18:22 | 490.9701 | 6/21 5:18–8:07 | 490.9708 | 7/2 16:21–18:38 | 490.9695 | 490.9703 | 0.6 |
4 | 6/14 5:02–7:55 | 430.9443 | 6/1 15:51–18:09 | 430.9438 | 7/5 6:06–8:37 | 430.9457 | 6/22 15:45–18:40 | 430.9440 | 430.9445 | 0.9 |
5 | 6/2 4:42–7:23 | 426.4424 | 6/13 15:37–18:02 | 426.4414 | 6/23 4:50–7:31 | 426.4426 | 7/1 16:15–18:19 | 426.4423 | 426.4422 | 0.5 |
6 | 6/13 4:30–7:31 | 426.3462 | 6/2 16:12–18:40 | 426.3450 | 7/1 4:40–7:07 | 426.3465 | 7/4 16:17–18:42 | 426.3463 | 426.3460 | 0.7 |
7 | 6/3 4:47–7:42 | 426.3831 | 6/12 16:25–18:49 | 426.3822 | 6/25 4:58–7:52 | 426.3835 | 6/30 15:44–17:48 | 426.3823 | 426.3828 | 0.6 |
8 | 6/10 4:40–7:45 | 430.5900 | 6/4 15:45–18:19 | 430.5913 | 6/30 4:55–7:14 | 430.5908 | 7/5 16:14–18:31 | 430.5919 | 430.5910 | 0.8 |
9 | 6/5 4:50–7:26 | 426.3055 | 6/9 15:33–18:13 | 426.3045 | 6/26 5:02–7:32 | 426.3071 | 6/29 16:16–18:21 | 426.3061 | 426.3058 | 1.1 |
10 | 6/8 5:50–8:32 | 426.3147 | 6/5 15:45–18:14 | 426.3146 | 6/29 5:23–7:52 | 426.3155 | 6/26 16:21–18:29 | 426.3150 | 426.3150 | 0.4 |
11 | 6/6 4:47–7:34 | 426.7336 | 6/7 15:57–18:19 | 426.7327 | 6/27 4:53–7:23 | 426.7344 | 6/28 16:12–18:20 | 426.7333 | 426.7335 | 0.7 |
12 | 6/7 5:15–8:08 | 430.1305 | 6/6 16:09–18:52 | 430.1303 | 6/28 5:18–7:48 | 430.1310 | 6/27 16:22–18:45 | 430.1305 | 430.1306 | 0.3 |
Total | 5129.5870 | 5129.5808 | 5129.5943 | 5129.5867 | 5129.5872 | 5.5 |
The 1894 M7.0 Shonai earthquake
Local map of the source region of the 1894 Shonai earthquake. The red lines denote the Eastern Shonai Plain fault zone. The pink ellipse denotes the area of severe damage (seismic intensity 5+ or larger). SB denotes the location of the Shionohara baseline. MOGA, SHIN, TACH are the GEONET stations
Fault parameters of the 1894 Shonai earthquake and its tested ranges and assumed sampling in the Monte Carlo simulations
Model parameter | Range | Sampling |
---|---|---|
Magnitude (Mw) | 6.8, 6.9, 7.0, 7.1, 7.2 | |
Fault center | 38.85ºN–38.95ºN, 139.95ºE–140.00ºE | Gaussian |
Fault depth (D) | 0.0–5.0 km | Random |
Fault length (L) | Scaling from Mw (Takemura 2005) | Gaussian |
Fault width (W) | W = 0.5 L | Gaussian |
Strike (ϕ) | N10°W–N10°E | Random |
Dip (δ) | 20º–50º | Random |
Rake (λ) | 70º–110º | Random |
Slip | Determined from Mw, L and W | |
Rigidity | 30 GPa | Fixed |
Poisson’s ratio | 0.25 | Fixed |
Monte Carlo simulation results for the length change of the Shionohara baseline due to the 1894 Shonai earthquake. Each curve shows a probability distribution of expected baseline length change for different moment magnitude obtained from 1 million test cases
There can be a significant deformation due to postseismic deformation of the Shonai earthquake. Such a postseismic deformation was observed, for example, following the 2008 Iwate-Miyagi earthquake (Ohzono et al. 2012). According to Ohzono et al. (2012), the postseismic deformation may have added extension to the coseismic one on the hanging-wall side at the distance from 20 to 30 km, and the extension rate was around 1 ppm/year. Thus, it is reasonable to assume that, in the case of the Shonai earthquake, the coseismic change had a larger effect on the Shionohara baseline by an order of magnitude than the postseismic deformation.
In summary, we conclude that it is highly possible that the 1894 Shonai earthquake elongated the Shionohara baseline by as large as 5 cm or 10 ppm.
Scale bias effects in the triangulation
Strain bias due to a + 5 cm error of the Shionohara baseline. a Arrows indicate principal strain axes, and dilatational bias is shown by colors. b Bias in the maximum shear strain
We also show distribution of the maximum shear strain change in Fig. 6b. The effect of the baseline bias is negligible (less than 1 ppm) for the maximum shear strain. The result is consistent with the fact that shear strain can be obtained only from angle measurements (e.g. Frank 1966). Fukushima et al. (2012) compared the shear strain distribution based on both triangulation data and GPS results before 2011 and concluded that E–W contraction has been continued over the twentieth century although the shortening might be enhanced in the southern Tohoku area. Our calculation result supports their conclusion.
Crustal strain during the 100 years after correction of scale bias. a Case of + 5 cm of the Shionohara baseline. b Case of + 10 cm
We also tested correction of the possible 1894 Shonai earthquake in the original triangulation. For this purpose, we hypothesize two fault models of the 1894 Shonai earthquake (source parameters are shown in Table 4), corresponding to 5 and 10 cm of the Shionohara baseline elongation. Then we calculate coseismic displacement at benchmarks using the elastic dislocation code by Okada (1985) and corrected the triangulation angles measured before the 1894 earthquake. We conducted network adjustments using these corrected angles and baseline length for two cases and evaluate the expected crustal strain distribution (Additional file 1: Figure S1). These corrected crustal strain distributions show some notable changes from those in Fig. 7, for example, in the degree of the N–S extension due to the scale bias. However, the overall strain patterns do not change from those in Fig. 7 and the effect of coseismic angle changes is not serious. Since the hypothetical fault model contains large uncertainties, we prefer to present Fig. 7 to demonstrate the scale bias effects on the triangulation result.
Re-survey of the Shionohara baseline
As is already mentioned, the control points at both ends of the Shionohara baseline still exist at their original positions. The current length of the baseline may provide an additional constraint on the coseismic disturbance of the 1894 Shonai earthquake. Therefore, we conducted the baseline length survey in August 2012.
Photographs of the first-order triangulation control points of the Shionohara baseline (photographs taken by T. Sagiya). a Western end. b Eastern end
Measured coordinates and length of the Shionohara baseline
East | West | Length (m) | ||
---|---|---|---|---|
1894 | GRS80* | 38º50′1.19570″N | 38º49′50.42285″N | 5129.6096 |
140º 21′35.39900″E | 140º18′3.17182″E | |||
Bessel** | 38º49′50.7913″N | 38º49′40.0249″N | 5129.5872 | |
140º21′47.6756″E | 140º18′15.4319″E | |||
2012 | GRS80*** | 38º50′1.16550″N | 38º49′50.39528″N | 5129.6767 |
140º21′35.48986″E | 140º18′3.25970″E | |||
Bessel* | 38º49′50.76110″N | 38º49′39.99733″N | 5129.6526 | |
140º21′47.76646″E | 140º18′15.51979″E |
In order to compare the baseline length in 2012 with that in 1894, we need to consider effects of various earthquakes in the surrounding areas and interseismic deformation during last 100 years. Among them, the 2011 Tohoku-oki earthquake contributed to the largest baseline change. Two GEONET baselines, Mogami (MOGA)-Shinjo (SHIN) (15.6 km) and Shinjo (SHIN)-Tachikawa (TACH) (31.4 km) aligned in the E–W direction nearly parallel to the Shionohara baseline (see Fig. 4 for locations), had length changes of ~ 0.25 m (+ 16.0 ppm) and ~ 0.50 m (+ 15.9 ppm), respectively, including coseismic as well as postseismic changes until August 2012. Thus, the total effects of the 2011 Tohoku-oki earthquake on the Shionohara baseline are evaluated as an elongation of around + 16 ppm (8 cm). Based on the GPS data before 2011, baseline length change rate for Mogami-Shinjo was nearly 0 and that of the Shinjo-Tachikawa was − 3 mm/year (− 0.1 ppm/year). It is reasonable to assume the interseismic shortening ratio of the Shionohara baseline as 0–0.1 ppm/year.
Major earthquakes around the Shionohara baseline and calculated baseline changes
Earthquake | Magnitude (Mw) | Coseismic (mm) | Postseismic (mm) | References |
---|---|---|---|---|
1894/10/22 Shonai * | 6.8 | + 50.3 | − 2.5 | |
7.0 | + 100.5 | − 4.9 | ||
1896/6/15 Sanriku | 8.5 | + 3.0 | + 1.1 | Tanioka and Satake (1996) |
1896/8/31 Rikuu | 7.2 | + 3.2 | − 5.2 | Thatcher et al. (1980) |
1897/8/5 Miyagi-oki | 7.7 | + 1.4 | + 0.6 | Aida (1977) |
1900/5/12 Northern Miyagi | 6.2 | + 0.1 | + 0.1 | Takemura (2005) |
1933/3/3 Sanriku | 8.4 | − 3.5 | − 3.0 | Abe (1978) |
1936/11/3 Miyagi-oki | 7.2 | + 0.6 | + 0.1 | Yamanaka and Kikuchi (2004) |
1937/7/27 Miyagi-oki | 7.1 | + 0.1 | 0.0 | Yamanaka and Kikuchi (2004) |
1938/5/23–1938/11/7 Shioyazaki-oki | 7.0, 7.5, 7.3,7.4, 6.9 | − 0.6 | − 0.4 | Abe (1977) |
1962/4/30 Northern Miyagi | 6.2 | + 0.5 | + 0.6 | Sato (1989) |
1964/6/16 Niigata | 7.6 | + 8.0 | + 3.0 | Abe (1975) |
1968/5/16 Tokachi-oki | 8.2 | − 0.4 | − 0.5 | Aida (1978) |
1970/10/16 SE Akita | 6.2 | − 0.2 | 0.0 | Mikumo (1974) |
1978/6/12 Miyagi-oki | 7.5 | + 1.5 | − 0.5 | Seno et al. (1980) |
1983/5/26 Japan Sea | 7.7 | − 1.1 | − 0.4 | Sato (1985) |
2003/7/26 Northern Miyagi | 6.1 | + 0.1 | 0.0 | Nishimura et al. (2003) |
2005/8/16 Miyagi-oki | 7.2 | + 0.6 | 0.0 | GSI (2005) |
2008 Iwate-Miyagi | 7.2 | + 11.3 | 0.0 | Takada et al. (2009) |
Two scenarios of length change history of the Shionohara baseline
Discussion
We first summarize our hypothesis about the Shionohara baseline and related consequences. The Shionohara baseline was measured during May–July 1894, and the value of 5129.5872 m was obtained with an expected precision of ~ 1 ppm. On October 22 of the same year, the Shonai earthquake happened and the baseline length was increased by about 10 ppm. However, the baseline was never re-surveyed after the earthquake and the original value was used for network adjustment. As a result, the triangulation network in northeast Japan was defined with a negative isotropic scale bias of 5–10 ppm, or the network was defined 5–10 ppm smaller than its actual size. After the first survey, tectonic plate motion and interplate coupling at the Japan trench accumulated E–W contraction roughly at 0.1 ppm/year as a regional average. After 100 years from the first survey, the cumulative contraction reaches about 10 ppm in E–W direction. In the comparison of triangulation data, the E–W contraction signal was not identified since the original network was defined smaller by almost the equal amount to the cumulative contraction during 100 years. Instead, the comparison of triangulation surveys revealed extensive N–S extension because the original network size was underestimated in N–S direction, too. This hypothesis explains why we did not identify geodetic signals showing tectonic strain accumulation in the Tohoku area.
The N–S extension in the Tohoku area was pointed out as early as in 1971 by Harada and Kassai (1971) who compared the re-survey of the triangulation network in the Showa era (1948–1968) with the original solution in the nineteenth century. By using Frank’s (1966) method, Sato (1973) and Nakane (1973a, b) evaluate shear strain rate of Japan Islands. They also estimated the maximum contraction in the Tohoku area was in the E–W direction, but this estimate was consistent with the N–S extension since the applied method could not resolve the dilatation. Later, Hashimoto (1990) and Ishikawa and Hashimoto (1999) estimated horizontal crustal strain rates using multiple survey results and reached a similar conclusion to Harada and Kassai (1971). Hashimoto and Jackson (1993) discussed interseismic deformation using angle change rate and concluded interseismic coupling at the Japan Trench was weak. Though there have been so many studies using triangulation data, no reasonable interpretation has been given about the observed N–S extension signal before. The observational error of the original triangulation in the nineteenth century was considered as large as 10 ppm based on the internal consistency of the network adjustment (Komaki 1985). But all the previous authors considered that the observation error was random and they did not consider a possibility of the scale bias as pointed out in this study. Hashimoto (1990) and Ishikawa and Hashimoto (1999) calculated strain rates from baseline length change rates using network adjustment results of all the available surveys. In the calculation of baseline length change rate, even with a large formal error, data from the first survey are highly influential since they are the only data in the first half of the analysis period.
The measurement of the Shionohara baseline finished in early July of 1894. However, according to the record, angle measurements of the first-order benchmarks continued until October of the same year. We speculate that the survey team should know that the Shonai earthquake occurred just after their survey. Only 3 years before the Shonai earthquake, there occurred the 1891 Nobi earthquake, which heavily affected the nearby triangulation network and the first recovery survey took place. Thus, there remains a question why a similar recovery survey was not conducted around the Shionohara baseline. While the town of Sakata to the west of the source fault was heavily damaged, almost no damage was reported in Shinjo close to the survey area (Omori 1895). Probably the survey team did not expect such a significant deformation to occur at the baseline.
Scale bias derived from the baseline length error is very extensive as is shown in Fig. 6, but it does not cause any inconsistency in the adjustment result. So, it is very difficult to recognize from the network adjustment. On the other hand, erroneous angle measurements can be easily identified through the network adjustment with large residuals. It is a fatal fault that we have overlooked the possibility of such a scale error. Since everybody knows that triangulation survey has a weakness in its scale, we should have investigated the unbiased observables such as angles or shear strains. Also, those who discuss seismic potential using geodetic data should understand how those data were obtained and what kind of errors could be contained.
In spite of such annoying data errors, conventional geodetic data such as triangulation and leveling still keep their scientific value. Our observation history with precise instruments such as GPS is still only 25–30 years long. Many geological phenomena such as earthquakes and volcanic eruptions are all unique, and we still lack of experience to make forecast or prediction on what happens in the future. In order to fully utilize the legacy of old observations, we should pay the most careful attention to data quality and various errors contained in the observation data.
On the other hand, it was nothing but an unfortunate coincidence that such a bias sneaked in the triangulation data. If the baseline had been constructed in a different place, if the baseline had been designed in the N–S direction, if the earthquake had occurred several months earlier, if the earthquake had been a little smaller or even larger, if one of us had been careful enough to investigate such a possibility, we could have avoided such an erroneous interpretation. This example provides a very important lesson that we can never be too careful in preparing for future natural hazard.
Conclusion
We revisited the original record of the Shionohara baseline survey conducted in 1894 and confirmed that the survey was conducted normally with a good precision. But we also found a possibility that the baseline length was significantly affected by the Shonai earthquake that occurred only 30 km to the west of the baseline. We numerically investigated a possible effect of the Shonai earthquake to the Shionohara baseline length and found that an earthquake with magnitude 6.9–7.0 could effectively elongate the baseline length as much as 5 cm or 10 ppm. Network adjustment calculations demonstrate that an error of 10 ppm at the Shionohara baseline causes significant as well as extensive scale bias in the strain calculation. A bias of 10 ppm was large enough to conceal tectonic strain accumulation over 100 years and to create apparent N–S extension signal over the entire Tohoku area. The re-survey of the Shionohara baseline was done in August 2012, after the 2011 Tohoku-oki earthquake. In spite of a large uncertainty in the interseismic deformation rate, the result is consistent with the hypothesis of the baseline scale bias. Thus, our understanding of no significant elastic strain accumulation in the Tohoku area before the 2011 Tohoku earthquake was caused by the isotropic scale bias of ~ 10 ppm in the original triangulation network adjustment result, for which coseismic deformation of the 1894 Shonai earthquake was responsible.
Notes
Author’s contributions
TS planned the whole research, conducted data analysis and field survey, and wrote the manuscript. NM and YO cooperated in the field survey. All members read the manuscript and agreed on the content.
Acknowledgements
Critical comments by Paul Segall, an anonymous reviewer, and an associate editor Tomokazu Kobayashi were helpful to improve the manuscript. Angela Meneses-Gutierrez, Shinichi Nomura and Syota Suzuki are acknowledged for their support in the field survey. Takuya Nishimura and Hiroshi Yarai are acknowledged for their support in gathering triangulation data and reading original field/calculation logs in the archives. We also thank the Geospatial Information Authority of Japan for the use of GEONET data.
Competing interests
The authors have no competing interest.
Availability of data and materials
All the data used in this manuscript can be provided on request.
Consent for publication
Not applicable.
Ethics approval and consent to participate
Not applicable.
Funding
This study was supported by JSPS KAKENHI Grant Numbers JP25282111 and JP26109003, and “Intensified Observation and Research on Strain Concentration Zone” project by the Ministry of Education, Culture, Sport, Science and Technology.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary material
References
- Abe K (1975) Re-examination of the fault model for the Niigata earthquake of 1964. J Phys Earth 23:349–366CrossRefGoogle Scholar
- Abe K (1977) Tectonic implications of the large Shioya-oki earthquakes of 1938. Tectonophys 41:269–289CrossRefGoogle Scholar
- Abe K (1978) A dislocation model of the 1933 Sanriku earthquake consistent with the tsunami waves. J Phys Earth 26:381–396CrossRefGoogle Scholar
- Aida I (1977) Simulations of large tsunamis occurring in the past off the coast of the Sanriku district. Bull Earthq Res Inst 52:71–101 (in Japanese with English abstract) Google Scholar
- Aida I (1978) Reliability of a tsunami source model derived from fault parameters. J Phys Earth 26:57–73CrossRefGoogle Scholar
- Ando M (1971) A fault-origin model of the great Kanto earthquake of 1923 as deduced from geodetic data. Bull Earthq Res Inst 49:19–32Google Scholar
- Frank FC (1966) Deduction of earth strains from survey data. Bull Seism Soc Am 56:35–42Google Scholar
- Fujii Y, Sugita K, Nakane K (1986) Earth’s horizontal strain in the north-east Japan (II). J Geod Soc Jpn 32:43–55Google Scholar
- Fukushima Y, Hashimoto M, Segall P (2012) Comparison of strain rates during the historical (1880–1990s) and GPS periods over northeastern Honshu before the 2011 Tohoku-oki earthquake, Program and Abstracts, Seismol. Soc. Japan 2012 Fall Meeting, C21–09Google Scholar
- Geospatial Information Authority of Japan (2005) Crustal deformation associated with the 2005 Miyagi-oki earthquake (in Japanese). http://www.gsi.go.jp/cais/HENDOU-hendou25.html
- Harada T, Kassai A (1971) Horizontal strain of the crust in Japan for the last 60 years. J Geod Soc Jpn 17:4–7 (in Japanese with English abstract) Google Scholar
- Hashimoto M (1990) Horizontal strain rates in the Japanese islands during interseismic period deduced from geodetic surveys (Part 1): honshu, Shikoku and Kyushu. Zisin 43:19–26 (in Japanese with English abstract) CrossRefGoogle Scholar
- Hashimoto M, Jackson DD (1993) Plate tectonics and crustal deformation around the Japanese Islands. J Geophys Res 98:16149–16166CrossRefGoogle Scholar
- Hashimoto C, Noda A, Sagiya T, Matsu’ura M (2009) Interplate seismogenic zones along the Kuril-Japan trench inferred from GPS data inversion. Nat Geosci 2:141–144CrossRefGoogle Scholar
- Headquarters for the Earthquake Research Promotion (2009) Evaluation of the eastern Shonai plain fault zone (in Japanese). https://www.jishin.go.jp/main/chousa/katsudansou_pdf/19_shonai-heiya_2.pdf
- Heki K, Miyazaki S, Tsuji H (1997) Silent fault slip following an interplate thrust earthquake at the Japan Trench. Nature 386:595–598CrossRefGoogle Scholar
- Igarashi T, Matsuzawa T, Hasegawa A (2003) Repeating earthquakes and interplate aseismic slip in the northeastern Japan subduction zone. J Geophys Res. https://doi.org/10.1029/2002JB001920 Google Scholar
- Ishikawa N, Hashimoto M (1999) Average horizontal strain rates in Japan during interseismic period deduced from geodetic surveys (Part 2). Zisin 52:299–315 (in Japanese with English abstract) CrossRefGoogle Scholar
- Ishikawa N, Tada T, Hashimoto M (1998) Horizontal strain in Japanese islands. Rep Geogr Surv Inst 89:18–26Google Scholar
- Ito T, Yoshioka S, Miyazaki S (2000) Interplate coupling in northeast Japan deduced from inversion analysis of GPS data. Earth Planet Sci Lett 176:117–130CrossRefGoogle Scholar
- Kawasaki I, Asai Y, Tamura Y (2001) Space-time distribution of interplate moment release including slow earthquakes and the seismo-geodetic coupling in the Sanriku-oki region along the Japan trench. Tectonophys 330:267–283CrossRefGoogle Scholar
- Komaki K (1985) The readjustment of the Meiji first order triangulation network by the projection method. Bull Geogr Surv Inst 29:1–45Google Scholar
- Komaki K (1993) Horizontal crustal movements revealed by geodetic measurements–Applications of a new method for estimating displacement vectors. J Geod Soc Jpn 39:387–410Google Scholar
- Matsuzawa T (2011) Why could the M9 earthquake occur in the northeastern Japan subduction zone? Why did we believe it would not occur there? Kagaku 81:1020–1026 (in Japanese) Google Scholar
- Mazzotti S, Le Pichon X, Henry P, Miyazaki S (2000) Full interseismic locking of the Nankai and Japan-west Kurile subduction zones: an analysis of uniform elastic strain accumulation in Japan constrained by permanent GPS. J Geophys Res 105:13159–13177CrossRefGoogle Scholar
- Mikumo T (1974) Some considerations on the fault mechanism of the southeastern Akita earthquake of October 16, 1970. J Phys Earth 22:87–108CrossRefGoogle Scholar
- Muto K (1932) A study of displacements of triangulation points. Bull Earthq Res Inst 10:384–392Google Scholar
- Nakane K (1973a) Horizontal tectonic strain in Japan (I). J Geod Soc Jpn 19:190–199Google Scholar
- Nakane K (1973b) Horizontal tectonic strain in Japan (II). J Geod Soc Jpn 19:200–208Google Scholar
- Nishimura T, Imakiire T, Yarai H, Ozawa T, Murakami M, Kaidzu M (2003) A preliminary fault model of the 2003 July 26, M6.4 northern Miyagi earthquake, northeastern Japan, estimated from joint inversion of GPS, leveling, and InSAR data. Earth Planets Space 55:751–757. https://doi.org/10.1186/BF03352484 CrossRefGoogle Scholar
- Nishimura T, Hirasawa T, Miyazaki S, Sagiya T, Miura S, Tanaka K (2004) Temporal change of interplate coupling in northeastern Japan during 1995-2002 estimated from continuous GPS observations. Geophys J Int 157:901–916CrossRefGoogle Scholar
- Ohzono M, Ohta Y, Iinuma T, Miura S, Muto J (2012) Geodetic evidence of viscoelastic relaxation after the 2008 Iwate-Miyagi Nairiku earthquake. Earth Planets Space 64:759–764. https://doi.org/10.5047/eps.2012.04.001 CrossRefGoogle Scholar
- Okada Y (1985) Surface deformation due to shear and tensile faults in a half-space. Bull Seism Soc Am 75:1135–1154Google Scholar
- Omori F (1895) Report of the Shonai earthquake on October 22 in Meiji 27. Shinsai Yobo Chousakaiho 28:79–95Google Scholar
- Sagiya T, Miyazaki S, Tada T (2000) Continuous GPS array and present-day crustal deformation of Japan. PAGEOPH 157:2303–2322Google Scholar
- Sato H (1973) A study of horizontal movement of the Earth crust associated with destructive earthquakes in Japan. Bull Geogr Surv Inst 19:89–137Google Scholar
- Sato T (1985) Rupture characteristics of the 1983 Nihonkai-Chubu (Japan Sea) earthquake as inferred from strong motion accelerograms. J Phys Earth 33:525–557CrossRefGoogle Scholar
- Sato R (1989) Handbook of earthquake fault parameters in Japan. Kajima Publishing, Minato-kuGoogle Scholar
- Seno T, Shimazaki K, Somerville P, Sudo K, Eguchi T (1980) Rupture process of the Miyagi-oki, Japan, earthquake of June 12, 1978. Phys Earth Planet Inter 23:39–61CrossRefGoogle Scholar
- Tada T (1986) Horizontal crustal strain in the northeastern Japan arc and its relation to the Tectonics. Zisin 39:257–265CrossRefGoogle Scholar
- Takada Y, Kobayashi T, Furuya M, Murakami M (2009) Coseismic displacement due to the 2008 Iwate-Miyagi Nairiku earthquake detected by ALOS/PALSAR: preliminary results. Earth Planets Space 61:e9–e12. https://doi.org/10.1186/BF03353153 CrossRefGoogle Scholar
- Takemura M (2005) Re-evaluation of magnitude and focal region of the 1900 Northern Miyagi Prefecture earthquake in Japan–Comparison with the 1962 and the 2003 events. Zisin 58:41–53CrossRefGoogle Scholar
- Tanioka Y, Satake K (1996) Fault parameters of the 1896 Sanriku tsunami earthquake estimated from tsunami numerical modeling. Geophys Res Lett 23:1549–1552CrossRefGoogle Scholar
- Thatcher W, Matsuda T, Kato T, Rundle JB (1980) Lithospheric loading by the 1896 Riku-u earthquake, northern Japan: implications for plate flexure and asthenospheric rheology. J Geophys Res 85:6429–9435CrossRefGoogle Scholar
- Usami T (2003) Latest version Japan earthquake damage overview 416-2001. University of Tokyo Press, TokyoGoogle Scholar
- Uyeda S, Kanamori H (1979) Back-arc opening and the mode of subduction. J Geophys Res 84:1049–1060CrossRefGoogle Scholar
- Wang R, Lorenzo-Martin F, Roth F (2006) PSGRN/PSCMP—a new code for calculation co- and post-seismic deformation, geoid and gravity changes based on viscoelastic-gravitational dislocation theory. Comput Geosci 32:527–541CrossRefGoogle Scholar
- Yamanaka Y, Kikushi M (2004) Asperity map along the subduction zone in northeastern Japan inferred from regional seismic data. J Geophys Res. https://doi.org/10.1029/2003JB002683 Google Scholar
Copyright information
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.