The Horizontal Kinematics of the North Island of New Zealand

<p>The advantages and disadvantages of the 'displacement' approach and the 'strain' approach to the analysis of repeated geodetic surveys for crustal deformation are discussed and two methods of geodetic strain analysis are described in detail. Repeated geodetic surveys in the central North Island show i) secular widening of the Taupo Volcanic Zone (TVZ) at 7 mm y-1 without significant transcurrent motion ii) north-south dextral motion at 14 mm y-1 and east-west narrowing at 4 mm y-1 across the northern end of the North Island Shear Belt iii) 3.1 m extension at 135' across a 15 km-wide region north of Lake Taupo, and adjacent zones of compressive rebound all associated with the 1922 Taupo Earthquakes. From the epicentral distribution and horizontal strain pattern a 15 km-square fault dipping 40' and striking parallel to the TVZ is inferred for the 1922 earthquakes. The seismic moment, 1.3 x 10 26 dyne cm, and the stress drop, 134 bars, are abnormally high for the TVZ. Widening of the TVZ is considered to be back-arc spreading. The spreading axis is postulated to extend northeast into the Havre Trough via a north-south dextral transform; and southwest into the Waverley Fault Zone and Waimea Depression via the sinistral reverse Raetihi Transform. Deformation of the North Island is not homogeneous. Fault zones are idealized as line plate boundaries and four plates -Indian, Central, Kermadec and Pacific - are postulated to account for the deformation. The Indian-Pacific macroplate pole is adopted and non-unique positions and rotation rates for the remaining poles are determined from geodetic strain data and the geometry of plate interactions. The Central Plate is moving away from the Indian Plate at the back-arc spreading axis; the Kermadec Plate is moving dextrally with respect to the Central Plate at the North Island Shear Belt which accommodates most of the transcurrent component of motion between the Indian and Pacific plates in the North Island and gives almost pure subduction of the Pacific Plate under the Kermadec Plate at the Hikurangi Margin.</p>

The Horizontal Kinematics of the North Island of New Zealand

<p>The advantages and disadvantages of the 'displacement' approach and the 'strain' approach to the analysis of repeated geodetic surveys for crustal deformation are discussed and two methods of geodetic strain analysis are described in detail. Repeated geodetic surveys in the central North Island show i) secular widening of the Taupo Volcanic Zone (TVZ) at 7 mm y-1 without significant transcurrent motion ii) north-south dextral motion at 14 mm y-1 and east-west narrowing at 4 mm y-1 across the northern end of the North Island Shear Belt iii) 3.1 m extension at 135' across a 15 km-wide region north of Lake Taupo, and adjacent zones of compressive rebound all associated with the 1922 Taupo Earthquakes. From the epicentral distribution and horizontal strain pattern a 15 km-square fault dipping 40' and striking parallel to the TVZ is inferred for the 1922 earthquakes. The seismic moment, 1.3 x 10 26 dyne cm, and the stress drop, 134 bars, are abnormally high for the TVZ. Widening of the TVZ is considered to be back-arc spreading. The spreading axis is postulated to extend northeast into the Havre Trough via a north-south dextral transform; and southwest into the Waverley Fault Zone and Waimea Depression via the sinistral reverse Raetihi Transform. Deformation of the North Island is not homogeneous. Fault zones are idealized as line plate boundaries and four plates -Indian, Central, Kermadec and Pacific - are postulated to account for the deformation. The Indian-Pacific macroplate pole is adopted and non-unique positions and rotation rates for the remaining poles are determined from geodetic strain data and the geometry of plate interactions. The Central Plate is moving away from the Indian Plate at the back-arc spreading axis; the Kermadec Plate is moving dextrally with respect to the Central Plate at the North Island Shear Belt which accommodates most of the transcurrent component of motion between the Indian and Pacific plates in the North Island and gives almost pure subduction of the Pacific Plate under the Kermadec Plate at the Hikurangi Margin.</p>

A Yakut Composite Bow from the Toybokhoy Museum

We give the fi rst description of an unusual composite bow of the Central Asian type, owned by the Toybokhoy Museum in the Suntarsky District of Yakutia, and provide information about its discovery. We foc us on the details and structural peculiarities of the specimen, and note that this refl ex composite bow differs in terms of construction and technology from those of the Northe rn type used by the Yakuts in the 17th to 19th centuries. It resembles bows of the Central Asian type. Its distinctive features are eight horn and bone frontal plates, four end-plates, and four long edging-plates made of bone. According to folkloric sources and 17th century archival documents, before the Russians migrated to the Lena Territory, the Yakuts had used bone combat bows of the Central Asian type. We cite an archaeological fact demonstrating the use of such bows in Yakutia—a central plate from a composite bow with widening paddle-shaped ends from the mid-15th to early 16th century burial at Sergelyakh. We publish the results of the radiocarbon analysis of the horn plate from the Toybokhoy bow, carried out at the Center for Isotope Research at the University of Groningen. They support the legendary version: the Toybokhoy bow belonged to the brother of the Yakut ruler Tygyn Darkhan, Ala Kyrsyn, who lived in the early 17th century and became the founder of one of the Vilyuy Yakut clans. We conclude that alongside the Northern type bows, the late medieval Yakuts used refl ex bows of the Central Asian type.

A new species of Wesmaelius Krüger from Mexico, with a key to the New World species of the subgenus Kimminsia Killington (Neuroptera, Hemerobiidae)

Wesmaelius (Kimminsia) nanacamilpa Marquez &amp; Contreras, sp. n., a brown lacewing from Tlaxcala state, Mexico is described and illustrated. This is the second recorded species of Wesmaelius from Mexico, and the third from Middle America. Males of the new species may be identified by parameres separate apically, styliform sclerites directed basally, as well as a rounded gonarcus with a short entoprocessus. Females may be distinguished from closely related species by a subgenital plate with the central plate broadly incised basally. There are now 16 species of Wesmaelius known from the New World.

Description of the first new species of Leuctridae (Plecoptera) from Jiangsu Province of China

The first new species of Leuctridae (Plecoptera) from Jiangsu Province of eastern coastal China, Rhopalopsole vespertilio sp. nov. is described and illustrated. The new species belongs to the R. magnicerca species group and is distinguished by the bat-like shaped central plate of tergum 10, by the medially narrowed subtrapezoidal transverse bars, and by the upcurved hook formed by the small epiproct. The new species is compared with similar taxa.

Mathematical model of mechanical testing of bone-implant (4.5 mm LCP) construct

The study deals with the possibility of substituting time- and material-demanding mechanical testing of a bone defect fixation by mathematical modelling. Based on the mechanical model, a mathematical model of bone-implant construct stabilizing experimental segmental femoral bone defect (segmental ostectomy) in a miniature pig ex vivo model using 4.5 mm titanium LCP was created. It was subsequently computer-loaded by forces acting parallel to the long axis of the construct. By the effect of the acting forces the displacement vector sum of individual construct points occurred. The greatest displacement was noted in the end segments of the bone in close proximity to ostectomy and in the area of the empty central plate hole (without screw) at the level of the segmental bone defect. By studying the equivalent von Mises stress σEQV on LCP as part of the tested construct we found that the greatest changes of stress occur in the place of the empty central plate hole. The distribution of this strain was relatively symmetrical along both sides of the hole. The exceeding of the yield stress value and irreversible plastic deformations in this segment of LCP occurred at the acting of the force of 360 N. These findings are in line with the character of damage of the same construct loaded during its mechanic testing. We succeeded in creating a mathematical model of the bone-implant construct which may be further used for computer modelling of real loading of similar constructs chosen for fixation of bone defects in both experimental and clinical practice.

A reapprisal of Barsboldia sicinskii (Dinosauria: Hadrosauridae) from the Late Cretaceous of Mongolia

The taxonomy and phylogenetic position of the hadrosaurid dinosaur Barsboldia sicinskii is revised. This species is rediagnosed based on the unique combination of iliac central plate with depth/length ratio less than 0.8 and sacral vertebrae with distally ‘clubbed’ neural spines at least four times higher than their centra. A maximum parsimony analysis of 47 hadrosauroid (39 hadrosaurid) species does not support the purported lambeosaurine affinities of B. sicinskii, but recovers this form as a basal saurolophine hadrosaurid based on unambiguous synapomorphies of the ilium. This result increases the diversity of saurolophine taxa in Asia, a continent with a hadrosaurid fossil record so far dominated by lambeosaurines. Finally, several vertebral and iliac characters previously regarded as diagnostic of Lambeosaurinae are discussed and shown to be uninformative from a taxonomic or phylogenetic standpoint.