Regional and teleseismic event detection capability of the small-aperture Tripoli seismic array, Greece

The Tripoli Seismic Array (TRISAR) is a small-aperture array designed to monitor and locate the seismicity in the area of Greece. In this study, its detection capabilities are discussed for regional and teleseismic events. A reference event list is compiled, consisting of events ofmb>5.0for regional and teleseismic distances (A>6°), according to the ISC On-line Bulletin. TRISAR automatically detected approximately 25% of these events over the entire investigated distance range. Although TRISAR slowness vector residuals are rather large, as expected for an array of such small aperture, the benefits resulting from the use of such a system for reporting regional and teleseismic activity is obvious.

Analisa Receiver Function Teleseismic untuk Mendeteksi Moho pada Stasiun Bkb Data Meramex

<span>It has been done a research to determine internal earth using receiver function teleseismic analysis <span>method. This method have been done by using MERAMEX (MErapi Amphibious Experiment) data from <span>broadband seismometer BKB. Event of teleseismic is chosen from Honshu Japan with radius 30<span>o <span>and <span>magnitude 7.2. This research begun by analysing radial and vertical characteristic of teleseismic event<br /><span>and using bandpass filter with range 0.003 Hz – 0.5 Hz. Then Iteractive Deconvolution is used to get <span>velocity model. The result of this model shows crustal model that has 4 Km thick upper crust, a 26 Km <span>thick lower crust and 10 Km thick Moho transition zone, with velocity increasing gradually.</span></span></span></span></span></span><br /></span></span></span>

Detection of Teleseismic Events in Seismic Sensor Data Using Nonlinear Dynamic Forecasting

In this paper we consider the use of nonlinear dynamic (NLD) forecasting as a signal processing tool for seismic applications. The specific problem considered here arises in monitoring nuclear tests and nuclear treaty compliance, where the presence of ubiquitous background noise obscures the seismic signals associated with the tests. The problem is that the signal from a distant teleseismic event can be attenuated so that it is lost in the background noise, and since the noise overlaps the frequency band occupied by the teleseisms, frequency-based techniques provide only marginal improvements in detection capabilities. For the work in this paper, we studied a test set of actual seismic sensor data prepared by the Air Force Technical Applications Center (AFTAC). The data set was composed of background seismic noise which contained or had added to it a number of hidden teleseismic signals. This data was analyzed to determine if techniques of NLD forecasting could be used to detect the hidden signals. For this test case, it was possible to predict the behavior of the seismic background sufficiently well that when the predicted background behavior was removed, the hidden signals became evident. However, some of the weaker signals were very close to the residual noise level, so the ability to detect these events is compromised.