The stress tensor orientation was estimated based on inversion from 238 first motion fault plane solutions of earthquakes with mostly M = 3.5 + 0.6 located in the 10-km radius Kaoiki cmstal volume. Separate inversions for subvolumes containing 20-50 events yielded the same results in several adjacent volumes, suggesting that the stress tensor is homogeneous in those parts of the Kaoiki area and that the inversion results are stable and meaningful. Five spatial subsets of the data were found for which the orientation of at least one of the principal axes was different from that in the other sets by 200-80 ø and at confidence levels exceeding 95%. The volcano summits of Kilauea and Mauna Loa, and their rift systems, are identified as the source of stress in the Kaoiki cmst, because the greatest principal stress points to Kilauea and Mauna Loa. In addition, the strain tensor due to energy released by these 238 earthquakes was computed for the Kaoiki area, and several subvolumes of it, by summing the moment tensors. The moment tensor of each earthquake was constmcted from the individual fault plane solutions and from an estimate of the scalar moment derived from the moment-magnitude relationship. A comparison of the directions of strain and stress tensors showed close agreement for subvolumes with predominantly strike-slip faulting. In these volumes the inversion process for stress directions led to misfits of approximately equal size for the conjugate near vertical nodal planes. These observations are interpreted to show that in the strike-slip regime of the upper part of the cmst, neither of the nodal planes is preferred for faulting. Rupture probably occurs along the NW and along the NE striking nodal planes in separate earthquakes. Subvolumes with more decollement faulting showed significant differences of 300-40 ø between the principal strain and stress directions. In these volumes the near-horizontal nodal planes showed noticeably smaller misfits in the inversion for the stress directions. These facts are interpreted to indicate that the decollement plane is weak, allowing slip on it even if the principal stresses are inclined at a large angle to it. It is proposed that comparison of strain and stress tensor calculations may be able to differentiate between tectonic regimes uniform in strength (no well developed fault plane) and regimes in which a fault with low frictional strength dominates. As a function of time, significant rotations of the strain tensor by approximately 45 ø can be observed, which seem to be related to the occurrences of Kaoiki mainshocks. During three background periods of about 7 years each, the average strain tensor showed an orientation typical for predominant decollement faulting, while two premainshock periods of 2.5 years each showed an orientation closer to strike-slip faulting. It is proposed that this pattern may be repeated before the next Kaoiki mainshock. The strain released seismically is less than the geodetically observed strain by approximately an order of magnitude. (Stres...

Exploring land use change is crucial to planning land space scientifically in a region. Taking the ecological conservation area (ECA) in western Beijing as the study area, we employ ArcGIS 10.2, landscape pattern index and multiple mathematical statistics to explore the temporal and spatial variation of land use from 2000 to 2020. Patch-generating Land Use Simulation (PLUS), Future Land Use Simulation (FLUS) and Markov models were used to simulate and predict the current land use in 2020. The models were evaluated for accuracy, and the more accurate PLUS model was selected and used to simulate and predict the potential land use in the study area in 2030 under two management scenarios. The main findings of this research are: (1) From 2000 to 2020, the construction land increased constantly, and the area of cultivated land and grassland decreased significantly. (2) For predicting the spatial distribution of land use in the study area, the PLUS model was more accurate than the FLUS model. (3) The land-use prediction of the study area in 2030 shows that the area of grassland, forest and water is approximately equal to their corresponding value in 2020, but the construction land increased constantly by occupying the surrounding cultivated land. According to this research, the continuous decrease of cultivated land in favor of increasing construction land will cause losses to the ecological service function of the ECA, which is not beneficial to the sustainable development of the region. Relevant departments should take corresponding measures to reduce this practice and promote sustainable development, particularly in the southern and western areas of the ECA where there is less construction land.

We report an abnormal room-temperature magnetoresistance behavior in self-doped Ag 2ϩ␦ Te films with Ag doping concentration ␦р0.25. Both positive magnetoresistance and negative magnetoresistance are found with the magnetic field applied along perpendicular to the sample surface and opposite direction, respectively. It is also evident from our study that such magnetoresistance ͑MR͒ behavior is strongly dependent on the doping concentration ␦ and the annealing time. The origin of the MR behavior is discussed and tentatively ascribed to the complex structure of the films, which is analyzed by x-ray measurement.Recently, there has been growing interest in the nonmagnetic compounds such as silver chalcogenides due to their large magnetoresistance ͑MR͒ effect. 1,2 Xu et al. 1 reported that the self-doped silver chalcogenides, Ag 2ϩ␦ Te and Ag 2ϩ␦ Se (␦Ϸ0.01ϳ0.33), possess a large MR ratio, ⌬/, up to 400% at 4.5 K and 60 kOe ͑120% at room temperature and 40 kOe͒. Later, large MR ratio of 300% at 50 K and 70 kOe ͑60% at room temperature and 50 kOe͒ was also observed in Ag 1.73 Te thin films by Chuprakov and Dahmen. 2 The temperature dependence of the MR of the films is different from that of the bulk material. 1 Although it was already proposed to be related with the carrier density, microstructure and other physical factors in the samples, however, the mechanism of the MR of self-doped silver chalcogenides is still not clear now.In this paper, we report an abnormal MR behavior in Ag self-doping Ag 2ϩ␦ Te films. Both positive magnetoresistance ͑MR-p͒ and negative magnetoresistance ͑MR-n͒ are obtained with the magnetic field applied along two opposite directions, ϩz and Ϫz axis. Here z axis is defined as the field direction perpendicular to the film surface and the magnetic field H applied along ϩz and Ϫz directions correspond to positive magnetic field (ϩH) and negative magnetic field (ϪH) during the MR measurements, respectively. Such abnormal MR behavior occurs only when ␦р0.25 in the Ag 2ϩ␦ Te films annealed at 430°C for 3 h. If the annealing time tϾ3 h or ␦Ͼ0.3, only MR-p is observed. The possible origin of the MR behavior is also discussed.Ag-Te multilayers were prepared on 22ϫ22 mm 2 glass substrates by using electron-beam evaporation with the base pressure better than 10 Ϫ6 Torr in the chamber. The evaporation rate of Ag and Te was about 0.5 Å/s, which was controlled by a quartz crystal monitor. The structure of the films was: substrate/Ag(400 Å)/Te(500 Å)/Ag(d Ag )/Te(200 Å)/ Ag(200 Å), where different values of the Ag thickness d Ag were used for different samples in order to vary the Ag doping concentration ␦ in the Ag 2ϩ␦ Te thin films. The asdeposited films were annealed in situ at about 10 Ϫ6 Torr for alloying. The Ag doping concentration ␦ was first selected by calculating stoichiometry for the films and further examined by an inductively coupled plasma-atomic emission spectrometer 3 ͑Thermo Jarrell-Ash Corp., IRIS/AP͒ after the films were prepared. In our experiments the doping concentration ␦ was 0.2, 0....

Soil moisture (SM), as the fundamental water source for vegetation (Miguez-Macho & Fan, 2021), dominates the ecosystem productivity (L. Liu, Gudmundsson, et al., 2020) and regulates terrestrial carbon uptake variability through land-atmosphere interactions (Humphrey et al., 2021). Among all interactions between SM and environmental factors, SM-temperature couplings significantly impact near-surface climates (Seneviratne et al., 2006). An increase in temperature might enhance evaporative demand and thereby promote evapotranspiration, leading to lower SM availability. In turn, drying soil conditions can further increase temperature by growing sensible heat flux, which is particularly responsible for temperature extremes such as heat waves (Seneviratne et al., 2010). Therefore, understanding the SM variations and their coupling strength with temperature is of vital importance for ecosystem and agriculture productivity and climate forecasting.Recently, two centuries-to-millennium summer SM series in dry inner Asia and southwest America was reconstructed by tree-ring width, and both studies suggest that the plunging SM in the past two decades was largely attributed to soaring temperature (Williams et al., 2020;Zhang et al., 2020) and enhanced by land-atmosphere interactions (Zhang et al., 2020). A hotter-drier regime seemed to be established in dry areas (Overpeck & Udall, 2020;Zhang et al., 2020). Although stronger SM-temperature couplings in dry regions than humid ones are commonly expected, SM also played an important role in temperature extremes in humid regions, such as the heatwave of 2003 in western Europe (WE) that resulted in tens of thousands of casualties (Miralles et al., 2014). However, to what extent the long-term SM variation has coupled with temperature over the past time in humid

The stress tensor orientation was calculated by inversion of 81 fault plane solutions of M = 3.5 ± 0.6 earthquakes located in an area 6 by 16 km at depths of 7 ± 2 km. This crustal volume is situated on a straight line between the summits of the active volcanoes Kilauea and Mauna Loa. The orientation of the greatest principal stress was found to be near horizontal and in the line connecting the two volcanoes. This is further evidence supporting the model that magmatic expansion within the feeding conduits of these volcanoes is the source of stress that causes earthquakes in southern Hawaii. These earthquakes are tectonic earthquakes in the sense that they occur in a brittle elastic crust at distances of a few to several tens of kilometers from the volcanoes, and that they are not directly associated with the opening of cracks by intrusions. We propose that this model leads to the corollary that the shear stresses (τ) responsible for earthquake failure in the shallow Hawaiian crust are approximately 3 ± 2 MPa, and that the pore pressure of ground‐water (p) in the hypocentral volume must be under near lithostatic pressure. This result is obtained by arguing that the greatest principal stress (σ1) is equal to the magma pressure in the volcanic feeder pipe, but cannot exceed the least principal stress (σ3) by more than the tensile strength of the crust, because otherwise hydrofracture would occur, opening a crack against the least principal stress. Given the difference between the greatest and least principal stress, the fact that the overburden at the 7 km hypocentral depth equals the intermediate principal stress and the ratio R = (σ1 − σ2)/(σ1 − σ3) = 0.4, which is obtained in the inversion of fault plane solutions, we estimate that σ1 = 202 MPa, σ2 = 200 MPa, σ3 = 196 MPa, τ = 3 MPa, and σn = 199 MPa, with uncertainties on the order of several MPa. It follows that for any coefficients of friction larger than 0.15, the pore fluid pressure necessary for faulting on the observed fault planes has to be larger than 90% of the lithostatic pressure. These considerations suggest that many earthquakes represent fault ruptures under low ambient shear stresses in the order of the average observed stress drop of 3 MPa.