Model metadata report for the Great Glen - Moray Firth merged Rockhead Elevation Model

The goal was to derive a merged onshore-offshore Rockhead Elevation Model (RHEM) for the Great Glen – Moray Firth Region (Figure 1), approximately 8622 km2. The purpose of the model was to: (i) provide a ‘capping surface’ for the 3D bedrock model of the area; (ii) enable calculation of Quaternary sediment volume and thickness distribution in the area; and (iii) explore combined GSI3D-GOCAD methodologies which could be used to produce this type of model. The resulting RHEM is suitable for interrogation but not fit for use at a higher resolution than 1:250 000

Women\u27s Equality Day Speech

Speech commemorating Women\u27s Equality Day, Fort Lee, NJ, August 26, 1984.https://ir.lawnet.fordham.edu/vice_presidential_campaign_speeches_1984/1011/thumbnail.jp

Extreme Sensitivity of the YORP Effect to Small-Scale Topography

Radiation recoil (YORP) torques are shown to be extremely sensitive to small-scale surface topography. Starting from simulated objects representative of the near-Earth object population, random realizations of three types of small-scale topography are added: Gaussian surface fluctuations, craters, and boulders. For each, the resulting expected relative errors in the spin and obliquity components of the YORP torque are computed. Gaussian power produces errors of order 100% if observations constrain the surface to a spherical harmonic order l < 10. A single crater with diameter roughly half the object's mean radius, placed at random locations, results in errors of several tens of percent. Boulders create torque errors roughly 3 times larger than do craters of the same diameter. A single boulder comparable to Yoshinodai on 25143 Itokawa, moved by as little as twice its own diameter, can alter the magnitude of the torque by factors of several, and change the sign of its spin component at all obliquities. A YORP torque prediction derived from groundbased data can be expected to be in error by of order 100% due to unresolved topography. Small surface changes caused by slow spin-up or spin-down may have significant stochastic effects on the spin evolution of small bodies. For rotation periods between roughly 2 and 10 hours, these unpredictable changes may reverse the sign of the YORP torque. Objects in this spin regime may random-walk up and down in spin rate before the rubble-pile limit is exceeded and fissioning or loss of surface objects occurs. Similar behavior may be expected at rotation rates approaching the limiting values for tensile-strength dominated objects.Comment: Icarus, accepted. 18 pp., 15 fi

Actively decaying or just poorly preserved? Can we tell when plant and invertebrate remains in urban archaeological deposits decayed?

We have recendy argued that poorly preserved delicate macrofossil remains of plants and invertebrates in near-surface deposits in York are in active decay, rather than being preserved in stasis, part-way down the decay trajectory. Observations of both archaeological and modern deposits suggest empirically that remains either survive for a long period (if conditions are conducive) or decay rapidly (if they are not). The hypothesis that very gradual decay has led to large numbers of deposits containing remains in a similar state appears illogical. It is more likely that, where poorly preserved biological remains are found, they either decayed in the past and then were stabilised when ground conditions became anoxic, or are currently in decay. Long-term patterns of decay cannot easily be investigated experimentally, but arguments concerning patterns and rates of decay can be. Apart from the question of in-ground preservation, understanding patterns of decay will allow us to address a range of taphonomic problems fundamental to drawing archaeological information from these remains