Peter I Island

Peter I Island in Fig. 16.40 is 19 km long and 11 km wide and rises to an elevation of 1,750 m above sea level. It has a steep coastline and is extensively covered by ice. The base of the island is circular and has a diameter of 64 km at a depth of 3,660 m. Therefore, Peter I Island is a large volcanic mountain that rises to a height of 5,240 m above the bottom of the surrounding ocean (Rowley 1990). 

After its discovery in 1821, Peter I Island has been visited only a few times for brief periods of time. In 

The summit contains a small crater about 100 m wide. The volcaiuc rocks of Peter I Island consist of basalt and trachyte flows with nunor amounts of volcanic breccia and lavas of intermediate composition. Some of the flows are highly vesicular. Pahoehoe structures have been reported, but no pillow lavas have been seen (i.e., the flows are snbaerial). The lava sequences are locally cut by basalt dikes and plugs. 

The basalt flows are gray to reddish brown, hypocrystalline to holocrystaUine, and partly porphy-ritic with phenocrysts of olivine (9.8-17.2%), plagio-clase (25.3-38.2%), and pyroxene in the matrix (30.0-41.6%). Chenucal analyses of five rock samples were published by Broch (1927), Craddock et al. (1964), and Bastien and Craddock (1976a, b). 

A K-Ar date of 12.8 1.5 Ma (Miocene) of an olivine basalt collected near sea level on Peter I Island was reported by Bastien and Craddock (1976a). In addition, the lack of erosion of the volcanic cone supports the conclusion that Peter I Island formed during the late Cenozoic. 

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Peter I Island is a large shield volcano in the Bellingshausen Sea at 68°51 S and 90 35 W and about 280 km north of the coast of Ellsworth Land in West Antarctica. Its principal claim to fame is that it was discovered by Captain Thaddeus von Bellingshausen on January 10, 1821, during his circumnavigation of Antarctica. 

Fig. 16.40 Peter I Island was discovered by Capteiin Thaddeus von Bellingshausen on January 10, 1821, who circumnavigated Antarctica in two small ships named Vostok and Mirny y (Section 1.1). The island is located in the Bellingshausen Sea about 280 km north of the coast of Ellsworth Land in West Antarctica Peter I Island is a shield volcano that rises from the sea floor at 3,660 m below sea level to a summit at 1,750 m above sea level. Therefore, the island is a large volcanic mounteiin that rises 5,240m from the bottom of the ocean. AK-Ar date of 12.8 1.5 Ma reported by Bastien and Craddock (1976a) indicates that the lava flows on Peter I Island were erupted during the Miocene (Adapted from Rowley (1990) in LeMasurier tmd Thomson (1990))...

Hart and Kyle (1993) also measured isotopic compositions of lead (i.e., the Pb/ Pb ratios) in the Cenozoic lavas of the HaUett volcanic province, the BaUeny Islands, as weU as of Scott and Peter I islands. The 206pb/204pb an(j 8 Sr/ Sr ratios of these rocks outline several overlapping areas in Fig. 16.42 that can be extrapolated to the HIMU component of the magma sources in the mantle (Zindler and Hart 1986 Hart 1988). 

The HIMU component typically has a high 206pb/204pb j. bo between 20.5 and 21.5 and a low Sr/ Sr ratio between 0.7025 and 0.7030 which places it in Fig. 16.42 on an extension of the hyperbolic Sr-Pb isotopic mixing line loosely defined by the Cenozoic volcanic rocks of the Hallett volcanic province. The volcanic rocks on the Balleny Islands and on Scott and Peter I islands have isotopic compositions of strontium and lead that overlap those of the Hallett volcanic province. However, the Sr/ Sr ratios of the Balleny/ Scott islands are low (0.7025-0.7030), whereas those of Peter I Island (0.7038-0.7040) are normal for oceanic island basalts. 

Some 200 tons of smallpox virus have been produced by the USSR as a weapon and inherited by Russia. Their fate is unclear. However, details of the development of smallpox as a weapon by the Soviets became available. A report was elicited from General Prof. Peter Burgasov, former Chief Sanitary Physician of the Soviet Army and a senior researcher within the BWP. Admitting that development of BW by the Soviets did take place, in the form of live field tests, he described a smallpox incident that happened in the 1970s, and was then hashed up On Vozrazhdenie Island in the Aral Sea, the strongest recipes of smallpox were tested. Suddenly I was informed that there were mysterious cases of mortalities in Aralsk. A research ship of the Aral fleet came 15 km away from the island (it was forbidden to come... 

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