clustering

Low-Frequency Earthquakes Downdip of Deep Slow Slip Beneath the North Island of New Zealand

We report the first catalog of low-frequency earthquakes in the Hikurangi subduction zone, located beneath the Kaimanawa Range of the North Island at 50 km depth, downdip of regularly recurring (every 4–5 years) deep M7 slow slip events. To …

Untangling the environmental and tectonic drivers of the Noto earthquake swarm in Japan

The underlying mechanism of the ongoing seismic swarm in the Noto Peninsula, Japan, which generates earthquakes at 10 times the average regional rate, remains elusive. We capture the evolution of the subsurface stress state by monitoring changes in …

A recursive matched-filter to systematically explore a volcanic long-period earthquake swarm

The matched-filter technique is an effective way to detect repeats, or near-repeats, of a seismic source, but prior identification of an event from that source to use as a template is required. We propose a recursive matched-filter approach to …

Tracking the Spatio-Temporal Evolution of Foreshocks Preceding the Mw 6.1 2009 L’Aquila Earthquake

How faulting processes lead to a large earthquake is a fundamental question in seismology. To better constrain this pre-seismic stage, we create a dense seismic catalog via template matching to analyze the precursory phase of the Mw 6.1 L’Aquila …

An adaptable random forest model for the declustering of earthquake catalogs

Earthquake catalogs are essential to analyze the evolution of active fault systems. The background seismicity rate, or rate of earthquakes that are not directly triggered by other earthquakes, directly relates to the stressing rate, a crucial …

Systematic Detection of Clustered Seismicity Beneath the Southwestern Alps

We present a new automated earthquake detection and location method based on beamforming (or back projection) and template matching and apply it to study the seismicity of the Southwestern Alps. We use beamforming with prior knowledge of the 3-D …

Progressive reactivation of the volcanic plumbing system beneath Tolbachik volcano (Kamchatka, Russia) revealed by long-period seismicity

After lying dormant for 36 yr, the Tolbachik volcano of the Klyuchevskoy group started to erupt on 27 November 2012. We investigate the preparatory phase of this eruption via a statistical analysis of the temporal behavior of long-period (LP) …

A Nonplanar Slow Rupture Episode during the 2000 Miyakejima Dike Intrusion

Magmatic intrusions release extensional strain in the Earth's crust upon availability of magma. Intrusions are typically accompanied by earthquake swarms and by surface faulting that is often larger than what is expected from the magnitude of the …

The evolving interaction of low-frequency earthquakes during transient slip

Observed along the roots of seismogenic faults where the locked interface transitions to a stably sliding one, low-frequency earthquakes (LFEs) primarily occur as event bursts during slow slip. Using an event catalog from Guerrero, Mexico, we employ …

Propagation of Coulomb Stress Uncertainties in Physics-Based Aftershock Models

Stress transfer between earthquakes is recognized as a fundamental mechanism governing aftershock sequences. A common approach to relate stress changes to seismicity rate changes is the rate-and-state constitutive law developed by Dieterich: these …