Shaking intensity from injection-induced versus tectonic earthquakes in the central-eastern United States

Susan E. Hough

doi:10.1190/tle34060690.1

Home/Archive/USGS

USGS · 70189616

Shaking intensity from injection-induced versus tectonic earthquakes in the central-eastern United States

Susan E. Hough

View original source ↗Export metadata ↓

Abstract

Although instrumental recordings of earthquakes in the central and eastern United States (CEUS) remain sparse, the U. S. Geological Survey's “Did you feel it?” (DYFI) system now provides excellent characterization of shaking intensities caused by induced and tectonic earthquakes. Seventeen CEUS events are considered between 2013 and 2015. It is shown that for 15 events, observed intensities at epicentral distances greater than ≈ 10 km are lower than expected given a published intensity-prediction equation for the region. Using simple published relations among intensity, magnitude, and stress drop, the results suggest that 15 of the 17 events have low stress drop. For those 15 events, intensities within ≈ 10-km epicentral distance are closer to predicted values, which can be explained as a consequence of relatively shallow source depths. The results suggest that those 15 events, most of which occurred in areas where induced earthquakes have occurred previously, were likely induced. Although moderate injection-induced earthquakes in the central and eastern United States will be felt widely because of low regional attenuation, the damage from shallow earthquakes induced by injection will be more localized to event epicenters than shaking tectonic earthquakes, which tend to be somewhat deeper. Within approximately 10 km of the epicenter, intensities are generally commensurate with predicted levels expected for the event magnitude.

Explore related subjects

The Leading Edge Article

Source-reported bounding extent: 32.76880048488168° to 44.77793589631623° latitude; -106.171875° to -79.89257812499999° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Susan E. Hough. 2015. Shaking intensity from injection-induced versus tectonic earthquakes in the central-eastern United States. https://doi.org/10.1190/tle34060690.1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2025

The Mammoth magnetic anomaly, Pinal County, Arizona

A high-resolution Earth Mapping Resources Initiative airborne geophysical survey was flown in the southwest North American porphyry copper province to improve bedrock geologic maps and to identify areas that have unrecognized critical mineral resource potential. During the review of the aeromagnetic data, a distinctly monopolar-shaped, negative magnetic anomaly was observed at a flight elevation of 200 m above the ground with a maximum amplitude of –9500 nT. We have named this the Mammoth magnetic anomaly (MMA) because it is centered 12 km northeast of the town of Mammoth, Arizona, USA. The total field anomaly (TFA) contour of –500 nT enclosing the MMA defines an elongate shape measuring 2.5 km long by 1 km wide that trends northwest–southeast. Given the striking nature of this negative, monopolar-shaped magnetic anomaly, we conducted a ground campaign in May 2025 to determine its authenticity and potential relationship to critical mineral endowment. The MMA was confirmed on the ground with a TFA approaching –46,000 nT. Total magnetic intensity (TMI) observations routinely fell below the 18,000 nT operating floor of an industry-standard cesium-vapor total field magnetometer, and extremely low TMI measurements were corroborated along coincident traverse lines using two high dynamic range, but lower sensitivity, smartphone vector magnetometers. The lowest TMI values recorded by both smartphone magnetometers were 1000 nT and confirmed with multiple adjacent and crossing lines. Field observations suggest that this magnetic feature is caused by strong remanent magnetization within fine-grained magnetite hosted within locally altered Pinal Schist.

Arizona↗

USGS2025

Drone-based radiometric surveys provide high-resolution mine waste characterization

Airborne radiometric surveys use passive geophysical techniques to characterize geochemical variations at or near earth’s surface. These methods have been used for a variety of mapping applications, including mineral resource evaluation. However, detailed characterization of smaller geologic targets, including mine waste features, requires flying at lower altitudes and with tighter line spacing than is feasible with traditional aircraft. Here, a small uncrewed aircraft system (sUAS) equipped with a radiometric sensor was used to acquire high-resolution gamma-spectrometry over small mine waste features and a low-grade stockpile in southwestern New Mexico. The sUAS radiometric system mapped local variability within each survey area and revealed ~2–10 m wide zones where radioelements K, Th, and U may be elevated 2–10× the surrounding material. Additionally, the sUAS radiometric data revealed radioelement variability across survey sites, which correlated reasonably well with variability seen in geochemical samples at each survey site, even though samples collected from individual sites showed high local variability. The sUAS data characterized local heterogeneity within mine waste and other small geologic targets at scales of a few meters to tens of meters, which is not possible with traditional crewed aircraft, and with continuity of coverage that is not possible with ground surveys, thus filling a key gap in geophysical survey spatial resolution.

New Mexico↗

USGS2024

Reviews

World Atlas of Submarine Gas Hydrates in Continental Margins , edited by Jürgen Mienert et al., ISBN 978-3-030-81185-3, Springer, 2022, 514 p., US$299.99 (print), $299.99 (e-book). The recently published World Atlas of Submarine Gas Hydrates in Continental Margins , edited by Mienert et al., provides a remarkably comprehensive global look at gas hydrates in continental margins. Given that approximately 99% of global gas hydrates are thought to exist on continental margins (the rest are in permafrost areas), this atlas covers the vast majority of gas hydrates on the earth. In addition to 37 geographically focused chapters covering essentially every continental margin on the planet (plus the Black Sea and Lake Baikal), the first six chapters review the history of gas-hydrate studies and fundamental considerations. The geographically focused chapters generally present a thorough description of geophysical and geologic observations from that area, written by an author or authors representing many years or decades of expertise there.

The Leading Edge↗