SUMMARY / RELATED TOPICS

Landslide

The term landslide or less landslip, refers to several forms of mass wasting that include a wide range of ground movements, such as rockfalls, deep-seated slope failures and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or underwater, in which case they are called submarine landslides. Gravity is the primary driving force for a landslide to occur, but there are other factors affecting slope stability that produce specific conditions that make a slope prone to failure. In many cases, the landslide is triggered by a specific event, although this is not always identifiable. Landslides occur when the slope undergoes some processes that change its condition from stable to unstable; this is due to a decrease in the shear strength of the slope material, to an increase in the shear stress borne by the material, or to a combination of the two. A change in the stability of a slope can be caused by a number of factors, acting alone.

Natural causes of landslides include: saturation by rain water infiltration, snow melting, or glaciers melting. Slope material that becomes saturated with water may develop into a debris mud flow; the resulting slurry of rock and mud may pick up trees and cars, thus blocking bridges and tributaries causing flooding along its path. Debris flow is mistaken for flash flood, but they are different processes. Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure and claim human lives. Muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage; as the impoundments fail, a "domino effect" may be created, with a remarkable growth in the volume of the flowing mass, which takes up the debris in the stream channel. The solid–liquid mixture can reach densities of up to 2,000 kg/m3 and velocities of up to 14 m/s; these processes cause the first severe road interruptions, due not only to deposits accumulated on the road, but in some cases to the complete removal of bridges or roadways or railways crossing the stream channel.

Damage derives from a common underestimation of mud-debris flows: in the alpine valleys, for example, bridges are destroyed by the impact force of the flow because their span is calculated only for a water discharge. For a small basin in the Italian Alps affected by a debris flow, estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same cross section, the maximum foreseeable water discharge, was 19 m3/s, a value about 40 times lower than that calculated for the debris flow that occurred. An earthflow is the downslope movement of fine-grained material. Earthflows can move at speeds within a wide range, from as low as 1 mm/yr to 20 km/h. Though these are a lot like mudflows, overall they are more slow moving and are covered with solid material carried along by flow from within, they are different from fluid flows. Clay, fine sand and silt, fine-grained, pyroclastic material are all susceptible to earthflows; the velocity of the earthflow is all dependent on how much water content is in the flow itself: the higher the water content in the flow, the higher the velocity will be.

These flows begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a rolling motion; as these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken; the bulbous variety of earthflows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are derived from the slumping at the source. Earthflows occur much more during periods of high precipitation, which saturates the ground and adds water to the slope content. Fissures develop during the movement of clay-like material which creates the intrusion of water into the earthflows. Water increases the pore-water pressure and re

SS Savoia

Savoia was a 5,490 ton refrigerated cargo ship, built in 1922. She was renamed Empire Arun. In 1947 she was renamed Granlake. Further name changes were Dryad in 1949, Shiranesan Maru in 1951 and Dainichi Maru in 1962, she was scrapped in 1968. Savoia was built by Trieste, she was yard number 736, launched on 25 May 1922 and completed on 1 December 1922. She was built for Navigazione Liberia Triestina and served with them until 1937 when she was transferred to Lloyd Triestino, Trieste on the demise of NLT. On 14 February 1941, Savoia was captured by HMS Hawkins at Kismayu, Italian Somaliland, she had been bound for Kenya. Savoia was taken as a war prize, renamed Empire Arun and passed to the Ministry of War Transport under the management of the Union-Castle Mail Steamship Co. Empire Arun was a member of a number of convoys during the Second World War. OS 17Convoy OS 17 sailed from Liverpool on 18 January 1942 and arrived at Freetown, Sierra Leone on 7 February. Empire Arun was carrying general cargo and was bound for Freetown, St Helena, Cape Town and East London.

SL 141Convoy SL 141 sailed from Freetown on 23 November 1943 and arrived at Liverpool on 17 December. Empire Arun was carrying a general cargo bound for Manchester. SC 156Convoy SC 156 sailed from Halifax, Nova Scotia on 29 March 1944 and arrived at Liverpool on 13 April. Empire Arun was carrying a general cargo bound for Liverpool SC 162Convoy SC 162 sailed from Halifax on 2 December 1944 and arrived at Liverpool on 17 December. Empire Arun was carrying a cargo of steel and general cargo bound for Manchester. In 1947, Empire Arun was sold to London and renamed Granlake, she was sold to Goulandris Bros, London that year. Granlake was sold to the Compagnia Maritime del Este, Panama in 1949 and renamed Dryad, operating under the management of Goulandris Bros Ltd. in 1951, Dryad was sold to Hikari Kisen KK, Tokyo and renamed Shiranesan Maru. She was sold to Mitsi Kinkai Kisen KK, Tokyo in 1953 and to Hokuyo Suisan KK, Tokyo in 1955. At this point she was in use as a crab cannery. In 1962, she was sold to Nichiro Gyogyo KK, who renamed her Dainichi Maru and used her as a shellfish cannery.

In 1969, Dainichi Maru was sold for scrap, arriving at Utsumi-Machi on 9 August 1969. Official Numbers were a forerunner to IMO Numbers. Savoia had the Italian Official Number 625 until 1932 and the Italian Official Number 115 from 1933-42. Empire Arun had the UK Official Number 159353 from 1942-47. Savoia used the Code Letters PGYH until 1933 and ICHB from 1934. Empire Arun used the Code Letters BCXG from 1942-47

Stromatopelminae

The Stromatopelminae are a subfamily of tarantulas native to West Africa and part of Central Africa. These arboreal tarantulas are found dwelling in the palm trees native to the West African region; the following genera and species are present in the Stromatopelminae: Encyocratella Strand, 1907Encyocratella olivacea Strand, 1907 Heteroscodra Pocock, 1899Heteroscodra crassipes Hirst, 1907 Heteroscodra crassipes latithorax Strand, 1920 Heteroscodra maculata Pocock, 1899 Stromatopelma Karsch, 1881Stromatopelma batesi Pocock, 1902 Stromatopelma calceatum Fabricius, 1793 Stromatopelma calceatum griseipes Pocock, 1897 Stromatopelma fumigatum Pocock, 1899 Stromatopelma pachypoda Strand, 1908 Stromatopelma satanas Berland, 1917 World Spider Catalog Tarantupedia Baboon Spiders Tropica