Benioff Vertical Seismogram; Galvanometer 2; Tg=13, 13.5, 14; To=1
Wood-Anderson Horizontal Torsion Seismograph No.1; EW
Wood-Anderson Horizontal Torsion Seismograph No.2; NS
Milne-Shaw Horizontal Pendulum Seismograph No.43; NW-SE; To=12sec; v=25degrees
Milne-Shaw Horizontal Pendulum Seismograph No.44; NE-SW; To=12sec; v=25degrees
photographic paper 36 inches x 14 inches
Of the 16,000 surviving analogue seismograms, 15% were damaged beyond recovery.
Paper records from 1989-1997 no longer exist.
no. available | years | format | dpi - front(back) | color - front(back) |
---|---|---|---|---|
~10,200 | 1933-1953 | tif, jpg | 1200(400) | color(grey scale) |
Seismograms can be downloaded from the Harvard Seismology website.
Some seismograms are available in SAC format. Vectorization is ongoing.
Harvard University develops and maintains the opensource code DigitSeis for vectorization of seismograms.
For more information on preservation efforts, see Ishii et al. (2015) and the HRV Seismogram Archival Project
For more information about this collection, please contact: Thomas Lee
Harvard Seismology. http://www.seismology.harvard.edu/HRV/status.html Last accessed 20 January 2022
Ishii, M., H. Ishii, B. Bernier, & E. Bulat (2015). Efforts to recover and digitize analog seismograms from Harvard- Adam Dziewonski observatory. Seismol. Res. Lett., 86(1):255-261.
Lee, T. A., M. Ishii, H. Ishii & T. Morinaga (2019). The Potential of Analog Seismograms for Science and Education, presented at 2019 Legacy Securing Legacy Seismic Data to Enable Future Discoveries Workshop, Albuquerque, New Mexico, Sept 18-19, 2019.
Photo Credit: Hornandsoccer, CC BY-SA 2.5, via Wikimedia Commons