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[1] Based on 6 months of OBS data from the Cascadia Initiative experiment near the Juan de Fuca Ridge, we obtain Rayleigh wave group and phase speed curves from 6 s to about 20 s period from ambient noise cross correlations among all station pairs. We confirm the hypothesis that the dispersion data can be fit by a simple age-dependent formula, which we invert using a Bayesian Monte Carlo formalism for an agedependent shear wave speed model of the crust and uppermost mantle between crustal ages of 0.5 and 3.5 Ma. Igneous crustal structure is age invariant with a thickness of 7 km, water depth varies in a prescribed way, and sedimentary thickness and mantle shear wave speeds are found to increase systematically with crustal age. The mantle model possesses a shallow low shear velocity zone (LVZ) with a velocity minimum at about 20 km depth at 0.5 Ma with lithosphere thickening monotonically with age. Minimum mantle shear velocities at young ages are lower than predicted from a half-space conductively cooling model (HSCM) and the lithosphere thickens with age faster than the HSCM, providing evidence for nonconductive cooling in the young lithosphere. The shallow LVZ is consistent with expectations for a largely dehydrated depleted (harzburgite) mantle with a small, retained near-ridge partial melt fraction probably less than 1% with melt extending to a lithospheric age of approximately 1 Ma (i.e., $30 km from the ridge).

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Grassland ecosystems in China have experienced degradation caused by natural processes and human activities. Time series segmentation and residual trend analysis (TSS-RESTREND) was applied to grasslands in eastern China. TSS-RESTREND is an extended version of the residual trend (RESTREND) methodology. It considers breakpoint detection to identify pixels with abrupt ecosystem changes which violate the assumptions of RESTREND. With TSS-RESTREND, in Xilingol (111°59′–120°00′E and 42°32′–46°41′E) and Hulunbuir (115°30′–122°E and 47°10′–51°23′N) grassland, 5.5% and 3.3% of the area experienced a decrease in greenness between 1984 and 2009, 80.2% and 73.2% had no significant change, 4.9% and 2.6% increased in greenness, and 9.4% and 20.9% were undetermined, respectively. RESTREND may underestimate the greening trend in Xilingol, but both TSS-RESTREND and RESTREND revealed no significant differences in Hulunbuir. The proposed TSS-RESTREND methodology captured both the time and magnitude of vegetation changes.

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Fine-scale population estimation is essential in emergency response and epidemiological applications as well as urban planning and management. However, representing populations in heterogeneous urban regions with a finer resolution is a challenge. This study aims to obtain fine-scale population distribution based on 3D reconstruction of urban residential buildings with morphological operations using optical high-resolution (HR) images from the Chinese No. 3 Resources Satellite (ZY-3). Specifically, the research area was first divided into three categories when dasymetric mapping was taken into consideration. The results demonstrate that the morphological building index (MBI) yielded better results than built-up presence index (PanTex) in building detection, and the morphological shadow index (MSI) outperformed color invariant indices (CIIT) in shadow extraction and height retrieval. Building extraction and height retrieval were then combined to reconstruct 3D models and to estimate population. Final results show that this approach is effective in fine-scale population estimation, with a mean relative error of 16.46% and an overall Relative Total Absolute Error (RATE) of 0.158. This study gives significant insights into fine-scale population estimation in complicated urban landscapes, when detailed 3D information of buildings is unavailable.

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