Provided is an earthquake response system using a seismic motion sensor. The seismic motion sensor of the earthquake response system includes: a sensor unit measuring a sensor value including peak ground acceleration (PGA) of the ground due to shaking; a seismic motion sensing unit sensing seismic motion on the basis of a seismic motion sensing result value calculated from an artificial neural network that uses the peak ground acceleration as input when the peak ground acceleration satisfies a seismic motion sensing condition; a seismic motion determiner determining generation of final seismic motion on the basis of a seismic motion determination parameter calculated from the sensor value on the basis of the seismic motion sensing result; a shaking grade calculator calculating a shaking grade of the determined final seismic motion through the peak ground acceleration; and a communication unit notifying the shaking grade of the final seismic motion.

Erroneous determination of noise as an earthquake is reduced in a seismic sensor. The seismic sensor operates in a power saving mode and a measurement mode in which power consumption is larger than that in the power saving mode. The seismic sensor includes: a measurement unit configured to measure acceleration; an earthquake determinator configured to transition from the power saving mode to the measurement mode when the acceleration measured by the measurement unit exceeds a predetermined threshold, to determine whether an earthquake is generated based on the acceleration measured in the measurement mode; and an index calculator configured to calculate an index value indicating a scale of the earthquake when the earthquake determinator determines that the earthquake is generated. The earthquake determinator determines whether the earthquake is generated by determining whether a predetermined condition is satisfied, the predetermined condition being determined based on the acceleration measured in at least one determination period, each determination period into which a period after the power saving mode transitions to the measurement mode is divided being set to a processing unit, and the measurement mode transitions to the power saving mode when the earthquake determinator determines that the earthquake is not generated.

Various embodiments herein relate to systems and methods for detecting seismic events. Systems may include inertial sensors distributed on or in communication with a network of optically switchable windows in the building. In some systems, inertial sensors are located within a window controller, within an insulated glass unit, or in some way rigidly attached to the structure of a building. Logic is described for leveraging sensed inertial data to predicted a seismic event and/or evaluate the structural health of the building. In some cases, logic may be used to issue an alert to building occupants about impending shear waves that will arrive at the building's location. In some cases, a window network may respond to a detected seismic event by, e.g., changing the optical state of windows and/or providing occupants with evacuation instructions.

Apparatus and methods are described, including identifying an arrival of a first arriving S-wave emitted from a seismic source at an array (120) of sensors (129, 140) in real-time, by continuously analyzing waveforms received by the sensors (120, 140), and continuously monitoring back-azimuth and slowness data within the detected waveforms. Arrival of a first arriving P-wave emitted from the seismic source at the array (120) of sensors (129, 140) is identified, based upon the back-azimuth and slowness data. Slowness and back azimuth of the first arriving P-wave are determined, by analyzing a waveform of the P-wave, and based upon the determined slowness of the first arriving P-wave, the arrival of the first arriving S-wave at the array (120) of sensors (129, 140) is identified. Other applications are also described.

A retrofit valve shutoff device comprises a coupling key for coupling with an actuator of a shutoff valve, an accelerometer for making acceleration measurements in three directions, a motor, and a processing unit. The processing unit determines the arrival of seismic P-waves when the ratio of vibrations' power in the vertical direction with respect to a sum of the vibrations' power in the three directions exceeds a first threshold. The processing unit then determines the arrival of seismic S-waves when the sum of the vibrations' power in the three directions exceeds a second threshold. The processing unit then determines the arrival of seismic surface waves when the sum of the vibrations' power in the three directions exceeds a third threshold. The processing unit then sends a signal to the motor to rotate the coupling key and the actuator of the shutoff valve to close the shutoff valve.

A seismic observation device includes an input unit receiving input of time-series data of measurement values of a vibration, a processing target determination unit determining a time period of the time-series data that is a processing target, and a type determination unit acquiring a likelihood of classifying a cause of the vibration indicated in the time-series data in the time period into each of types of cause.

A seismic warning system comprises: a plurality of sensors, each sensor sensitive to a physical phenomenon associated with seismic events and operative to output an electronic signal representative of the sensed physical phenomenon; a data acquisition unit communicatively coupled to receive the electronic signal from each of the plurality of sensors, the data acquisition unit comprising a processor configured to estimate characteristics of a seismic event based on the electronic signal associated with a P-wave from each of the plurality of sensors; and a local device communicatively coupled to the data acquisition unit. The plurality of sensors, the data acquisition unit and the local device are local to one another.

A building safety verification system and a building safety verification method for estimating a degree of damage of a building after an earthquake occurs are provided. The building safety verification system includes: an inter-story displacement measurement unit which obtains, from measurement data of acceleration sensors which measure accelerations of a plurality of stories in a building, an inter-story displacement of each of the stories; a natural period measurement unit which obtains a natural period of microtremor of the building from measurement data of a micro vibration sensor which measures micro vibration of a highest story of the building or a story near the highest story; and a building safety evaluation unit which evaluates soundness of the building from the inter-story displacement obtained by the inter-story displacement measurement unit and the natural period obtained by the natural period measurement unit.

A system and method for a distributed earthquake analysis and reporting system are provided. The system includes a facility control system at a facility that obtains earthquake information sent from one or more seismic sensors, and sends the earthquake information over a network directly or indirectly to other facility control systems. The facilities which include the facility control systems can be owned/operated by different business organizations or by the same organization, in examples. The facility control system at each facility responds to received earthquake information from the other facility control systems by configuring building systems such as public address systems to warn building occupants, industrial machine controllers to stop machinery, and elevator controllers to stop elevators at a nearest floor and open its doors, in examples.

A system and method for a distributed earthquake analysis and reporting system are provided. The system includes a facility control system at a facility that obtains earthquake information sent from one or more seismic sensors, and sends the earthquake information over a network directly or indirectly to other facility control systems. The facilities which include the facility control systems can be owned/operated by different business organizations or by the same organization, in examples. The facility control system at each facility responds to received earthquake information from the other facility control systems by configuring building systems such as public address systems to warn building occupants, industrial machine controllers to stop machinery, and elevator controllers to stop elevators at a nearest floor and open its doors, in examples.