5:15 PM - 7:15 PM
[SSS14-P17] Felt reports extracted from a historical diary “Chikusai Nikki” and its characteristics
Keywords:Felt reports, “Chikusai Nikki”, 1854 Kaei (Ansei) Tokai and Nankai earthquakes, Seismicity
The recent development of historical earthquake and volcanic activity databases using historical diaries (e.g., Nishiyama, 2019) has advanced historical earthquake studies based on felt reports documented in historical literature. These records serve as observation stations for seismic intensities. Collecting such data is crucial for analyzing seismicity during historical periods and reassessing past major earthquakes, including their substantiality. In the present study, we extracted felt reports from the historical diary "Chikusai Nikki (abbreviated as CN)" (Matsusaka University, 1991-1998), primarily documented in present-day Matsusaka, Mie Prefecture, identified periods of missing data, and analyzed temporal changes in the frequency of felt reports including occurrence times and descriptions of seismic intensities.
The CN was recorded by Chikusai Takegawa, the seventh head of the Higashi-Takegawa family, an Ise merchant based in Izawa-mura, Iino County, Ise Province. His primary business was money exchange, and he also functioned as an exchange agent for the Tokugawa shogunate. The seventy-five extant volumes of the diary, written in Takegawa’s own hand, are preserved in the Sowa Bunko. A facsimile of the original is housed in the Matsusaka City Library’s local archive and serves as the primary source for transliteration and deciphering, with original documents referenced as needed. Despite the missing periods, the diaries span 57 years from 1826 to 1882. Before his retirement, Takegawa frequently traveled between Izawa and Edo (modern Tokyo), and his records from 1830-1850 include descriptions of earthquakes he experienced in Edo.
Over one hundred felt reports were extracted from the diary over 52 years (1830-1881). The CN provides extensive descriptions of the 1854 Iga-Ueno earthquake and its damage, while the descriptions of the Tokai and Nankai earthquakes in the same year are minimal due to gaps in the diary. Additionally, felt reports from the Ise Izawa main residence (now Izawa Bunko, Takegawa’s residence) indicate a period without any felt reports several years before the 1854 Iga-Ueno, Tokai, and Nankai earthquakes, despite continuous diary entries.
Earthquake catalogs from instrumental observations suggest a possible seismic quiescence, characterized by reduced seismic activity, before major earthquakes such as the 1944 Tonankai and the 1946 Nankai earthquakes (e.g., Ogata, 2003). Similar seismic quiescence was reported before the 2011 Tohoku earthquake (e.g., Matsu’ura, 2008; Katsumata, 2011). However, the rarity of major earthquakes limits case studies on pre- and post-seismicity patterns. Felt reports from CN can serve as valuable observational data to reconstruct seismicity before and after the 1854 Tokai and Nankai earthquakes. This absence of felt reports may indicate seismic quiescence as suggested by Tsuji et al. (2005), although the careful examination of the quality (homogeneity and completeness) of felt reports in CN are required.
Acknowledgements
This study was supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan under The Third Earthquake and Volcano Hazards Observation and Research Program.
The CN was recorded by Chikusai Takegawa, the seventh head of the Higashi-Takegawa family, an Ise merchant based in Izawa-mura, Iino County, Ise Province. His primary business was money exchange, and he also functioned as an exchange agent for the Tokugawa shogunate. The seventy-five extant volumes of the diary, written in Takegawa’s own hand, are preserved in the Sowa Bunko. A facsimile of the original is housed in the Matsusaka City Library’s local archive and serves as the primary source for transliteration and deciphering, with original documents referenced as needed. Despite the missing periods, the diaries span 57 years from 1826 to 1882. Before his retirement, Takegawa frequently traveled between Izawa and Edo (modern Tokyo), and his records from 1830-1850 include descriptions of earthquakes he experienced in Edo.
Over one hundred felt reports were extracted from the diary over 52 years (1830-1881). The CN provides extensive descriptions of the 1854 Iga-Ueno earthquake and its damage, while the descriptions of the Tokai and Nankai earthquakes in the same year are minimal due to gaps in the diary. Additionally, felt reports from the Ise Izawa main residence (now Izawa Bunko, Takegawa’s residence) indicate a period without any felt reports several years before the 1854 Iga-Ueno, Tokai, and Nankai earthquakes, despite continuous diary entries.
Earthquake catalogs from instrumental observations suggest a possible seismic quiescence, characterized by reduced seismic activity, before major earthquakes such as the 1944 Tonankai and the 1946 Nankai earthquakes (e.g., Ogata, 2003). Similar seismic quiescence was reported before the 2011 Tohoku earthquake (e.g., Matsu’ura, 2008; Katsumata, 2011). However, the rarity of major earthquakes limits case studies on pre- and post-seismicity patterns. Felt reports from CN can serve as valuable observational data to reconstruct seismicity before and after the 1854 Tokai and Nankai earthquakes. This absence of felt reports may indicate seismic quiescence as suggested by Tsuji et al. (2005), although the careful examination of the quality (homogeneity and completeness) of felt reports in CN are required.
Acknowledgements
This study was supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan under The Third Earthquake and Volcano Hazards Observation and Research Program.