SUMMARY The Cameroon Volcanic Line (CVL) is an 1800‐km‐long line of Cenozoic volcanoes that does not show a chronological progression consistent with hotspot‐related volcanism. We investigate seismic anisotropy to determine the upper‐mantle lattice preferred orientation and constrain the mantle flow pattern using a temporary array of 32 broad‐band seismographs deployed throughout Cameroon between 2005 and 2007 along with two additional permanent seismographs in adjacent countries. We determine the fast direction and lag time beneath each station by stacking SKS and SKKS splitting measurements from multiple events. The results indicate four regions with different splitting parameters. The Congo Craton in southern Cameroon and the Garoua rift region in northeast Cameroon have northeast–southwest‐oriented fast directions and split times of about 1 s. Between the Congo Craton and the CVL, in central Cameroon, the fast directions are variable and have small splitting times of 0.3 s or less. Along the CVL, where previous studies show a strong slow velocity anomaly in the mantle, the fast direction is oriented approximately north–south, with splitting times of about 0.7 s. We interpret measurements from southern Cameroon and northeast Cameroon as indications of lattice‐preferred orientation frozen into the Congo Craton and subcontinental lithosphere related to relict plate motion and deformation. The distinct pattern of splitting along the CVL suggests the existence of small‐scale convection in the asthenosphere related to the formation of the CVL, perhaps driven by the adjacent cold edge of the Congo Craton.

A new version of the computer program 1DTempPro extends the original code to include new capabilities for (1) automated parameter estimation, (2) layer heterogeneity, and (3) time-varying specific discharge. The code serves as an interface to the U.S. Geological Survey model VS2DH and supports analysis of vertical one-dimensional temperature profiles under saturated flow conditions to assess groundwater/surface-water exchange and estimate hydraulic conductivity for cases where hydraulic head is known.

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Micro-earthquake activity is reported for the first 6 months of 2011 in Long Beach, CA using a density urban exploration seismic network. Detected events include at least four times as many man-made events as possible real earthquakes indicated by repeated locations, and distinct patterns in the hour-of-day and day-of-week origin times. Some discrimination appears possible utilized the earthquake spectral behavior in the wavelet transform domain. The back-projection of the seismic data onto a prescribed fault plane of the Newport-Inglewood fault produces interesting slip patterns over a time window spanning a small earthquake. Figure 1. Located Events. The left panel shows the location of the Long Beach array (small red dots), the stations of the Southern California Seismic Network (SCSN) (green dots), and the seismicity located by the SCSN (blue stars) during the 6-month deployment of the Long Beach Array (LB3D). The right panel shows the over 4,500 events located by the LB3D network.