A method of predicting parameters of an earthquake uses an array of ionosondes to scan an observed volume of an ionosphere located above a seismically active zone. The method includes monitoring ionograms provided by the array of ionosondes; detecting the presence of at least one seismic-induced irregularity (SII); determining a first predicted parameter corresponding to an epicenter location; and determining one or more predicted parameters selected from a group consisting of a magnitude, a time of occurrence, and a hypocenter depth. Algorithms for calculating the predicted parameters are presented in detail.

A method of predicting parameters of an earthquake uses an array of ionosondes to scan an observed volume of an ionosphere located above a seismically active zone. The method includes monitoring ionograms provided by the array of ionosondes; detecting the presence of at least one seismic-induced irregularity (SII); determining a first predicted parameter corresponding to an epicenter location; and determining one or more predicted parameters selected from a group consisting of a magnitude, a time of occurrence, and a hypocenter depth. Algorithms for calculating the predicted parameters are presented in detail.

This is an early warning method for a shallow soil landslide based on a digital topographic map, belonging to the field of landslide prevention and control engineering. It has following steps: a. connecting a straight line along an upward bulged intermediate point of a contour line of the topographic map as an intermediate line; b. determining an intermediate point; c. constituting a three-point group of a plane curvature; d. taking an arithmetic average of slopes as a slope ? of a landslide mass. The shallow soil landslide can be early warned without a lot of historical observation data of landslide occurrence, and the dangerous landslide mass can be determined in advance, which greatly improves the applicability of disaster prevention and the early warning efficiency.

A method and system are provided for acquiring the probability of slope failure and destabilization caused by an earthquake. For example, the method includes performing azimuth division in an area around a site at which a slope is located as a center, pre-setting a seismic acceleration threshold value that varies within a certain range, and calculating an exceeding probability that the seismic acceleration of the slope site generated by an earthquake in each azimuth domain is greater than or equal to the seismic acceleration threshold value, to establish an exceeding probability curve of site seismic acceleration corresponding to each azimuth domain. The method and system achieve estimation of the probability of slope destabilization caused by an earthquake by comprehensively considering the uncertainty of the seismic action and the uncertainty of slope failure and destabilization.

The invention provides a method of detecting a seismic event, which comprises acquiring (110) a digital signal x characteristic of a signal measured by at least one seismic sensor, and calculating (130) a time-frequency distribution for at least one section of a given duration of said signal, in a given frequency band. For each frequency of said frequency band, the calculated time-frequency distribution is normalized. The method also comprises calculating (150) the moving average of the normalized time-frequency distribution ZD, in said frequency band and in a time window, given reference L, centered on the time n; and detecting (160) a seismic event when the average exceeds a predefined threshold value. The invention also provides a corresponding detection system.

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.

Exemplary practice of the present invention provides an air vehicle and at least one interferometric double-path fiber optic sensor connected with the air vehicle. Each fiber optic sensor includes a pair of optical fibers, viz., an optical sensing fiber and an optical reference fiber, in a parallel and propinquus relationship. The paired optical fibers of each fiber optic sensor are attached to the air vehicle either (i) circumferentially around the fuselage or (ii) lengthwise along the fuselage or (iii) span-wise along the wings and across the fuselage, and are configured whereby the sensing fiber is exposed to the atmosphere and the reference fiber is not. Each fiber optic sensor senses atmospheric infrasound but does not sense atmospheric wind noise, which is negated by incoherency associated with design lengthiness of the optical fiber pair. Noise and strain due to temperature, vibration, and propulsion are neutralized via interferometric common mode rejection.

Fracture imaging modules having one or more 3-component sensors, are incorporated into a tool comprising two or more of the modules for detecting microseismic events in a formation from the same wellbore as is being stimulated. The modules are locked together in a compact mode to permit injection into the wellbore through a conventional lubricator which has a fixed length. Once injected into the wellbore, the modules are spaced from one another in an extended mode to form an axially spaced sensor array which increases the measurement window in the wellbore compared to sensor arrays conventionally injected through a fixed length lubricator. Following the operation, the modules are actuated to return to the compact mode for pulling out of the hole through the lubricator.

A method for monitoring depth of a cave front in a cave-type mine. The method includes: providing a stationary reader device and mobile marker devices, each of the marker devices adapted to (i) emit an electromagnetic signal, (ii) detect strength of the signal emitted by another of the marker devices, and (iii) wirelessly transmit information related to the detected signal via the other marker devices to the stationary reader device; drilling a hole into a rock region of a mine, installing the mobile marker devices at sequential known depths within the hole; monitoring the reader device to detect a decrease in the strength of a signal emitted by a first marker device by a second marker device; and in response to a decrease being detected by the second marker device, inferring the depth of the cave front to be between the known depths of the first and second marker devices.