The Impact of Globalization on Women: Testing Vandana Shiva’s Critique of Development

Vandana Shiva argues that through the masculinization of agriculture globalization has turned nature and women into passive fields for sowing. Shiva’s critique that international trade, and globalization more generally, has undermined the social and economic position of women in less developed countries provides a wealth of testable hypotheses. For example, Shiva’s argument implies that gender earnings inequality is higher in countries that are more integrated into the world economy, ceteris paribus. After summarizing her argument, we test this hypothesis through cross-sectional regression analysis.Gender Earnings Inequality; Vandana Shiva; Kuznets Curve

Large Earthquake Triggering, Clustering, and the Synchronization of Faults

Large earthquakes are sometimes observed to trigger other large earthquakes on nearby faults. The magnitudes of the calculated Coulomb stress transfers presumed to cause the triggering are 10⁻²–10⁻³ of the earthquake stress drops. The earthquake stress drops and the triggering delay times are similarly small with respect to the natural recurrence time of the earthquakes. This requires that both faults be simultaneously very close to the ends of their seismic cycles. Paleoseismological data show that for the same regions prior earthquakes have occurred in clusters of ruptures of several faults separated by long quiescent periods. Both observations suggest that synchronization is occurring between faults. Theory and observations indicate that synchronization can occur between nearby faults with positive stress coupling and intrinsic slip velocities within an entrainment threshold. In the south Iceland seismic zone, the central Nevada seismic belt, and the eastern California shear zone, several synchronous clusters that apparently act independently can be recognized. This behavior is the 3D equivalent of the phase locking that results in the seismic cycle of individual faults being dominated by large characteristic earthquakes, and for synchronization of fault segments along a given fault. Rupture patterns of repeated individual earthquakes or earthquake clusters are not identical in either the 2D or 3D cases. The state of this system, which exhibits strong indications of synchrony without exact repetition, may be called fuzzy synchrony

The Rupture Mode of the Shallow Large‐Slip Surge of the Tohoku‐Oki Earthquake

The remarkable feature of the Mw 9.1 Tohoku-Oki earthquake of 2011 was a late, shallow, surge that propagated from about 12 km depth all the way to the trench. This surge had very large slip and was depleted in high-frequency radiation. It was followed by normal faulting in the outer wedge; this requires that the postsurge basal shear stress be close to zero. Explanations for the surge propagating through the velocity-strengthening region by a thermal weakening mechanism fail to produce the near-total stress drop required by the postseismic extension. The surge propagated in a region of material contrast across the plate interface. The combination of a strong nucleation pulse from down dip, velocity strengthening, and the bimaterial effect satisfies the conditions for wrinkle pulse propagation. A wrinkle pulse rupture mode can produce an instability by overcoming velocity strengthening with the normal stress reduction produced by the bimaterial effect. It also leads to total stress drop, satisfying the extension constraint and explaining the prodigious slip amplitude of the surge. Because the surfaces are detached in wrinkle pulse mode, asperity contact is reduced, which explains the dearth of high-frequency radiation during the surge. This behavior appears to be a common feature of many of the greatest subduction earthquakes

On the stress dependence of the earthquake b value

Laboratory experiments have shown that the b value in the size distribution of acoustic emission events decreases linearly with differential stress. There have been a number of observations that indicate that this relation may also hold for earthquakes. Here using a simple frictional strength model for stresses in the continental lithosphere combined with earthquake b values measured as a function of depth in a wide variety of tectonic regions, we verify and calibrate that relation, finding b = 1.23 ± 0.06 − (0.0012 ± 0.0003)(σ1 − σ3), where the stress difference (σ1 − σ3) is in megapascal. For subduction zones, we find that b value correlates linearly with the slab pull force and with the net reduction of plate interface normal force, both of which also indicate a negative linear relation between b value and differential stress

The Brittle‐Ductile Transition Predicted by a Physics‐Based Friction Law

A theory of the brittle‐ductile transition (BDT) is shown to be a direct consequence of a recently developed physics‐based constitutive law for rock friction (Aharonov & Scholz, 2018, https://doi.org/10.1002/2016JB013829), which assumes exponential creep on contacts. The theory was previously tested against experimental data for sliding at low ambient temperature and stress. Here, theoretical interpretation of experimental data at high temperature and stress shows that at some point the real area of contact reaches a maximum value beyond which it becomes fixed. The constitutive law shows that this marks the onset of the BDT, beyond which sliding changes from frictional to an exponential flow law for low‐temperature plasticity. Application to the Earth's crust shows that beyond this point, strength fall linearly with depth until it intersects the power law for bulk flow of the country rock, which marks the lower boundary of the BDT. Modeling, constrained by experimental data for granite, predicts that the BDT starts at a temperature of about 300°C, at a depth of 11–13 km in the continental crust, depending on fault slip rate and temperature gradient. The completion of the BDT is similarly calculated to occur around 475°, at 16–18 km, in agreement with laboratory and field observations. The BDT is thus found to be a region spanning about 175°C with a width of several kilometers.Within the exponential flow region, the structural outcome would be a relatively narrow mylonitized fault zone, which widens into a broader region of shear at the base of the BDT

Slip-length scaling in large earthquakes' Observations and theory and implications for earthquake physics

For twenty years there has been a dilemma in earthquake physics, because the observed scaling law for large earthquakes did not appear to be consistent with the stress-drop invariance of small earthquake scaling. Surprisingly, slip was seen to continue to increase with rupture length L even for events with lengths much longer than the event widths W (the brittle crust down-dip depth), whereas it might have been expected to saturate for lengths much beyond the width. If this implies that the physics of great earthquakes is somehow different from that of their smaller counterparts, this casts serious doubts on predicting the effects of the rare and damaging great events from observations of the more common smaller events. Here we bring together recently compiled observations of very large aspect ratio earthquakes with results of a 3 dimensional dynamic earthquake model to show that slip-length scaling observations are, in fact, consistent with a scale-invariant physics. Further, we discuss the origin of the large earthquake scaling in the model

Calibration and alignment of metrology system for the Nuclear Spectroscopic Telescope Array mission

A metrology system to measure the on-orbit movement of a ten meter mast has been built for the Nuclear Spectroscopic Telescope Array (NuSTAR) x-ray observatory. In this paper, the metrology system is described, and the performance is measured. The laser beam stability is discussed in detail. Pre-launch alignment and calibration are also described. The invisible infrared laser beams must be aligned to their corresponding detectors without deploying the telescope in Earth’s gravity. Finally, a possible method for in-flight calibration of the metrology system is described

Quantum-Proof Multi-Source Randomness Extractors in the Markov Model

Randomness extractors, widely used in classical and quantum cryptography and other fields of computer science, e.g., derandomization, are functions which generate almost uniform randomness from weak sources of randomness. In the quantum setting one must take into account the quantum side information held by an adversary which might be used to break the security of the extractor. In the case of seeded extractors the presence of quantum side information has been extensively studied. For multi-source extractors one can easily see that high conditional min-entropy is not sufficient to guarantee security against arbitrary side information, even in the classical case. Hence, the interesting question is under which models of (both quantum and classical) side information multi-source extractors remain secure. In this work we suggest a natural model of side information, which we call the Markov model, and prove that any multi-source extractor remains secure in the presence of quantum side information of this type (albeit with weaker parameters). This improves on previous results in which more restricted models were considered or the security of only some types of extractors was shown