iShake: Mobile Phones as Seismic Sensors

Shideh Dashti, Jack Reilly, Jonathan Bray, Alex Bayen, Steven Glaser, Mari Ervasti

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

Abstract

A rapid and accurate portrayal of damage distribution after an earthquake is vital for an effective emergency response. Shortcomings still exist due to the limited number of strong motion stations and the qualitative nature of human observations used to construct ground-shaking intensity maps. In an effort to overcome the existing shortcomings, the iShake project proposes to use cell phones to measure ground motion intensity parameters and automatically deliver data to the U.S. Geological Survey (USGS) for processing and dissemination. Quantitative shaking data from numerous cellular phones will enable the USGS to produce shaking maps more accurately than presently possible. The phone sensor, however, is an imperfect device with performance variations among phones of a given model as well as between models. The sensor is the entire phone, not just the micro-machined transducer inside. A series of 1-D and 3-D shaking table tests were performed at UC San Diego and UC Berkeley, respectively, to evaluate the performance of a class of cell phones. In these tests, seven iPhones and iPod Touch devices that were mounted at different orientations were subjected to 124 earthquake ground motions to characterize their response and reliability as seismic sensors. The testing also provided insight into the seismic response of unsecured and falling instruments. The cell phones measured seismic parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and 5% damped spectral accelerations well. In general, iPhone and iPod Touch sensors slightly over-estimated ground motion energy (i.e., Arias Intensity, Ia). However, the mean acceleration response spectrum of the seven iPhones compared remarkably well with that of the reference high quality accelerometers. The error in the recorded intensity parameters was dependent on the characteristics of the input ground motion, particularly its PGA and Ia, and increased for stronger motions. The use of a high-friction device cover (e.g., rubber iPhone covers) on unsecured phones yielded substantially improved data by minimizing independent phone movement. Useful information on the ground motion characteristics was even extracted from unsecured phones during intense shaking events. The insight gained from these experiments is valuable in distilling information from a large number of imperfect signals from phones that may not be rigidly connected to the ground. With these ubiquitous measurement devices, a more accurate and rapid portrayal of the damage distribution during an earthquake can be provided to emergency responders and to the public.
Original languageEnglish
Title of host publicationAmerican Geophysical Union Fall Meeting 2010
Subtitle of host publicationAbstracts
Publication statusPublished - 2010
MoE publication typeNot Eligible
EventAmerican Geophysical Union Fall Meeting 2010 - San Francisco, United States
Duration: 13 Dec 201017 Dec 2010

Conference

ConferenceAmerican Geophysical Union Fall Meeting 2010
Abbreviated title2010 AGU Fall Meeting
CountryUnited States
CitySan Francisco
Period13/12/1017/12/10

Fingerprint

Mobile phones
Earthquakes
Geological surveys
Sensors
Seismic response
Accelerometers
Transducers
Rubber
Friction
Testing
Processing
Experiments

Keywords

  • Earthquake dynamics
  • Earthquake ground motions and engineering seismology
  • Seismic instruments and networks

Cite this

Dashti, S., Reilly, J., Bray, J., Bayen, A., Glaser, S., & Ervasti, M. (2010). iShake: Mobile Phones as Seismic Sensors. In American Geophysical Union Fall Meeting 2010: Abstracts [S51E-02]
Dashti, Shideh ; Reilly, Jack ; Bray, Jonathan ; Bayen, Alex ; Glaser, Steven ; Ervasti, Mari. / iShake: Mobile Phones as Seismic Sensors. American Geophysical Union Fall Meeting 2010: Abstracts. 2010.
@inbook{20def987ef84418baa5b9fc4d1e1eb8e,
title = "iShake: Mobile Phones as Seismic Sensors",
abstract = "A rapid and accurate portrayal of damage distribution after an earthquake is vital for an effective emergency response. Shortcomings still exist due to the limited number of strong motion stations and the qualitative nature of human observations used to construct ground-shaking intensity maps. In an effort to overcome the existing shortcomings, the iShake project proposes to use cell phones to measure ground motion intensity parameters and automatically deliver data to the U.S. Geological Survey (USGS) for processing and dissemination. Quantitative shaking data from numerous cellular phones will enable the USGS to produce shaking maps more accurately than presently possible. The phone sensor, however, is an imperfect device with performance variations among phones of a given model as well as between models. The sensor is the entire phone, not just the micro-machined transducer inside. A series of 1-D and 3-D shaking table tests were performed at UC San Diego and UC Berkeley, respectively, to evaluate the performance of a class of cell phones. In these tests, seven iPhones and iPod Touch devices that were mounted at different orientations were subjected to 124 earthquake ground motions to characterize their response and reliability as seismic sensors. The testing also provided insight into the seismic response of unsecured and falling instruments. The cell phones measured seismic parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and 5{\%} damped spectral accelerations well. In general, iPhone and iPod Touch sensors slightly over-estimated ground motion energy (i.e., Arias Intensity, Ia). However, the mean acceleration response spectrum of the seven iPhones compared remarkably well with that of the reference high quality accelerometers. The error in the recorded intensity parameters was dependent on the characteristics of the input ground motion, particularly its PGA and Ia, and increased for stronger motions. The use of a high-friction device cover (e.g., rubber iPhone covers) on unsecured phones yielded substantially improved data by minimizing independent phone movement. Useful information on the ground motion characteristics was even extracted from unsecured phones during intense shaking events. The insight gained from these experiments is valuable in distilling information from a large number of imperfect signals from phones that may not be rigidly connected to the ground. With these ubiquitous measurement devices, a more accurate and rapid portrayal of the damage distribution during an earthquake can be provided to emergency responders and to the public.",
keywords = "Earthquake dynamics, Earthquake ground motions and engineering seismology, Seismic instruments and networks",
author = "Shideh Dashti and Jack Reilly and Jonathan Bray and Alex Bayen and Steven Glaser and Mari Ervasti",
note = "Project code: 26357",
year = "2010",
language = "English",
booktitle = "American Geophysical Union Fall Meeting 2010",

}

Dashti, S, Reilly, J, Bray, J, Bayen, A, Glaser, S & Ervasti, M 2010, iShake: Mobile Phones as Seismic Sensors. in American Geophysical Union Fall Meeting 2010: Abstracts., S51E-02, American Geophysical Union Fall Meeting 2010, San Francisco, United States, 13/12/10.

iShake: Mobile Phones as Seismic Sensors. / Dashti, Shideh; Reilly, Jack; Bray, Jonathan; Bayen, Alex; Glaser, Steven; Ervasti, Mari.

American Geophysical Union Fall Meeting 2010: Abstracts. 2010. S51E-02.

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

TY - CHAP

T1 - iShake: Mobile Phones as Seismic Sensors

AU - Dashti, Shideh

AU - Reilly, Jack

AU - Bray, Jonathan

AU - Bayen, Alex

AU - Glaser, Steven

AU - Ervasti, Mari

N1 - Project code: 26357

PY - 2010

Y1 - 2010

N2 - A rapid and accurate portrayal of damage distribution after an earthquake is vital for an effective emergency response. Shortcomings still exist due to the limited number of strong motion stations and the qualitative nature of human observations used to construct ground-shaking intensity maps. In an effort to overcome the existing shortcomings, the iShake project proposes to use cell phones to measure ground motion intensity parameters and automatically deliver data to the U.S. Geological Survey (USGS) for processing and dissemination. Quantitative shaking data from numerous cellular phones will enable the USGS to produce shaking maps more accurately than presently possible. The phone sensor, however, is an imperfect device with performance variations among phones of a given model as well as between models. The sensor is the entire phone, not just the micro-machined transducer inside. A series of 1-D and 3-D shaking table tests were performed at UC San Diego and UC Berkeley, respectively, to evaluate the performance of a class of cell phones. In these tests, seven iPhones and iPod Touch devices that were mounted at different orientations were subjected to 124 earthquake ground motions to characterize their response and reliability as seismic sensors. The testing also provided insight into the seismic response of unsecured and falling instruments. The cell phones measured seismic parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and 5% damped spectral accelerations well. In general, iPhone and iPod Touch sensors slightly over-estimated ground motion energy (i.e., Arias Intensity, Ia). However, the mean acceleration response spectrum of the seven iPhones compared remarkably well with that of the reference high quality accelerometers. The error in the recorded intensity parameters was dependent on the characteristics of the input ground motion, particularly its PGA and Ia, and increased for stronger motions. The use of a high-friction device cover (e.g., rubber iPhone covers) on unsecured phones yielded substantially improved data by minimizing independent phone movement. Useful information on the ground motion characteristics was even extracted from unsecured phones during intense shaking events. The insight gained from these experiments is valuable in distilling information from a large number of imperfect signals from phones that may not be rigidly connected to the ground. With these ubiquitous measurement devices, a more accurate and rapid portrayal of the damage distribution during an earthquake can be provided to emergency responders and to the public.

AB - A rapid and accurate portrayal of damage distribution after an earthquake is vital for an effective emergency response. Shortcomings still exist due to the limited number of strong motion stations and the qualitative nature of human observations used to construct ground-shaking intensity maps. In an effort to overcome the existing shortcomings, the iShake project proposes to use cell phones to measure ground motion intensity parameters and automatically deliver data to the U.S. Geological Survey (USGS) for processing and dissemination. Quantitative shaking data from numerous cellular phones will enable the USGS to produce shaking maps more accurately than presently possible. The phone sensor, however, is an imperfect device with performance variations among phones of a given model as well as between models. The sensor is the entire phone, not just the micro-machined transducer inside. A series of 1-D and 3-D shaking table tests were performed at UC San Diego and UC Berkeley, respectively, to evaluate the performance of a class of cell phones. In these tests, seven iPhones and iPod Touch devices that were mounted at different orientations were subjected to 124 earthquake ground motions to characterize their response and reliability as seismic sensors. The testing also provided insight into the seismic response of unsecured and falling instruments. The cell phones measured seismic parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and 5% damped spectral accelerations well. In general, iPhone and iPod Touch sensors slightly over-estimated ground motion energy (i.e., Arias Intensity, Ia). However, the mean acceleration response spectrum of the seven iPhones compared remarkably well with that of the reference high quality accelerometers. The error in the recorded intensity parameters was dependent on the characteristics of the input ground motion, particularly its PGA and Ia, and increased for stronger motions. The use of a high-friction device cover (e.g., rubber iPhone covers) on unsecured phones yielded substantially improved data by minimizing independent phone movement. Useful information on the ground motion characteristics was even extracted from unsecured phones during intense shaking events. The insight gained from these experiments is valuable in distilling information from a large number of imperfect signals from phones that may not be rigidly connected to the ground. With these ubiquitous measurement devices, a more accurate and rapid portrayal of the damage distribution during an earthquake can be provided to emergency responders and to the public.

KW - Earthquake dynamics

KW - Earthquake ground motions and engineering seismology

KW - Seismic instruments and networks

M3 - Conference abstract in proceedings

BT - American Geophysical Union Fall Meeting 2010

ER -

Dashti S, Reilly J, Bray J, Bayen A, Glaser S, Ervasti M. iShake: Mobile Phones as Seismic Sensors. In American Geophysical Union Fall Meeting 2010: Abstracts. 2010. S51E-02