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 method for assessing a performance-based seismic design by setting a seismic risk starts from the exceedance probability of the performance level. The method is configured to determine the structural performance level by setting an exceedance probability, determine the seismic demand when the performance level is constant, set the exceedance probability of the seismic demand in combination with the seismic risk of a set earthquake to finally determine the ground motion input and establish a novel probabilistic seismic risk assessment method that reaches the performance level. The main control and objective of the design are significantly enhanced by using this method.

A building integrity assessment system includes: an earthquake detector including: a building bottom sensor at a bottom of a building and that detects acceleration and an earthquake early-warning receiver that receives an earthquake early warning; a cloud computer; and sensors disposed at a plurality of positions in the building and that measures an influence of an earthquake on the building at each of the positions and wirelessly transmits measurement results to the cloud computer. The cloud computer estimates and evaluates the integrity of the building based on the measurement results. In response to the building bottom sensor detecting preliminary tremors or the earthquake early-warning receiver receiving the earthquake early warning, the plurality of sensors measures the influence of the earthquake on the building from a time before a major motion arrives at the building to a time after the arrival.

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 seismic monitoring system includes a plurality of seismic monitors and a processing device operatively coupled to the plurality of seismic monitors. The processing device receives recordings of waveforms of motion detected at the plurality of seismic detectors in a geographic area. The processing device applies the respective recordings to corresponding positions of the seismic detectors in a three-dimensional geological model that describes its elastic attributes and tests a plurality of moment tensors at a plurality of locations. Based on the testing, the processing device determines a globally convergent source location and moment tensor in the three-dimensional model based on the testing.

A seismic sensor that suppresses power consumption operates in a power-saving mode and a measurement mode in which the power consumption is larger than that in the power-saving mode. The seismic sensor includes a measurement unit that measures an acceleration, a filtering unit that, if the acceleration measured by the measurement unit exceeds a predetermined threshold, causes a shift from the power-saving mode to the measurement mode to be performed, and performs filtering on the measured acceleration, an earthquake determination unit that determines whether or not an earthquake has occurred based on the filtered acceleration, and an index calculation unit that, if where the earthquake determination unit determined that an earthquake has occurred, calculates an index value indicating the scale of the earthquake. A shift from the measurement mode to the power-saving mode is performed if the earthquake determination unit determined that no earthquake has occurred.

A retrofit valve shutoff device is provided that comprises a coupling key for coupling with an actuator of a shutoff valve on a fluid supply line, an inertial measurement unit for generating one or more signals in response to arrival of seismic waves, a motor for rotating the coupling key and the actuator of the shutoff valve, and a processing unit for receiving the one or more signals from the inertial measurement unit, analyzing the received signals to determine whether to close the shutoff valve, and sending a signal to the motor to rotate the coupling key and the actuator of the shutoff valve to close the shutoff valve based on the analysis of the received signals.

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.

Novel solutions, which can include devices, systems, methods, than can measure earthquakes and other displacement events. Some solutions feature the integration of real-time, high-rate global navigation satellite system (GNSS) displacement information with acceleration and/or velocity data within a single device to create very high-rate displacement records. The mating of these two instruments allows the creation of a new, very high-rate displacement measurement device that has the full-scale displacement characteristics of GNSS and high-precision dynamic motions of seismic technologies. Such a device can be used for earthquake early warning studies and other mission critical applications, such as volcano monitoring, building, bridge and dam monitoring systems.

Power consumption of a seismic sensor is suppressed. The seismic sensor is operated in a power-saving mode and a measuring mode in which the power consumption is larger than that of the power-saving mode. The seismic sensor includes: a measuring part configured to measure an acceleration; an index calculator configured to transition from the power-saving mode to the measuring mode to calculate an index value indicating a size of an earthquake when the acceleration measured with the measuring part exceeds a first threshold; and a threshold adjuster configured to change the first threshold so as to increase the first threshold relative to a predetermined reference value when a tendency of the acceleration measured with the measuring part satisfies a predetermined condition.