| Title | Discriminating between low-magnitude shallow earthquakes and road construction blasts near Big Salmon River, New Brunswick, Canada |
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| Author | Kolaj, M |
| Source | Seismological Research Letters vol. 89, no. 5, 2018 p. 1966-1976, https://doi.org/10.1785/0220180077 |
| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180008 |
| Publisher | Seismological Society of America (SSA) |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Program | Canadian Hazard Information Service |
| Released | 2018 06 20 |
| Abstract | Spectral ratio discriminants were developed to discriminate between low-magnitude (MN<2MN<2) shallow (depth <3km<3km) earthquakes and blasts related to road construction. The spectral ratios were formed
from narrowband spectral?energy estimates between 1 and 40 Hz of Pg, Lg, and Rg for a total of 786 unique discriminants. From these discriminants, it was found that broadband high-frequency Pg/Lg and low?frequency Lg/Rg provided the largest
separation between earthquakes and blasts. The high-frequency Pg/Lg spectral ratio confirms the applicability of P/S ratios for the discrimination of low-magnitude blasts from small local/regional shallow earthquakes. Furthermore, the success of the
Lg/Rg spectral ratio demonstrates that the normalized Rg component from blasts typical of road construction projects tends to be larger at small epicentral distances (<50km<50km) than that of shallow earthquakes typical of the area. Although the
results presented in this work were developed for a local area, the broader conclusions are likely expandable to other regions in Canada, in particular the Northern Appalachians, where discriminating between low-magnitude blasts related to mining and
road construction and shallow earthquakes is a daily challenge. |
| Summary | (Plain Language Summary, not published)
Discriminating between blasts (e.g., construction and mining) and earthquakes is a daily challenge in Canada. A particular example of this was near Big
Salmon River in New Brunswick, Canada where both blasts (due to road construction) and earthquakes occurred in the same region. In this work, the ratios between specific seismic waves were shown to be able to discriminate between these two types of
events and, based on these results, nine questionable events were reclassified to known blasts and one to a known earthquake. |
| GEOSCAN ID | 308130 |
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