• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.360-360
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• 2017

Morphological characteristics indicating agronomic features and yield components (trunk length, trunk diameter, thickness of bark, pith density, dry-matter percentage of pith and starch concentration in pith) of sago palms (Metroxylon sagu Rottbøll) were compared between the 27 populations grown in the islands in Southeast Asia (West Sumatra, South Sumatra, West Java, Southeast Sulawesi, Ternate, Halmahera and Seram in Indonesia) and the 20 populations grown in Melanesia (West Papua in Indonesia, East Sepik and New Ireland island in Papua New Guinea). The average starch yield calculated based on the yield components was $310kg\;plant^{-1}$ and $244kg\;plant^{-1}$ in the islands in Southeast and Melanesia, respectively. The variation of starch yield in Melanesia (CV: about 80%) was larger than that in the islands in Southeast Asia (CV: about 60%). The difference in starch yield in the islands in Southeast Asia was mainly attributed to the trunk diameter breast height and the dry-matter percentage of pith. In contrast, the differences in trunk length and dry-matter percentage of pith mainly accounted for the difference in starch yield in Melanesia. The sago palms in the islands in Southeast Asia had a comparatively thick and short trunk and those in Melanesia had a comparatively thinner and longer trunk. However, the average pith dry-matter yield was almost same level as $400kg\;plant^{-1}$ in both the islands in Southeast Asia and Melanesia. The difference in starch yield between the two areas was attributed to the difference in starch concentration in pith, 77% and 58% in the islands in Southeast Asia and Melanesia, respectively.

• Ocean and Polar Research
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• v.35 no.4
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• pp.465-489
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• 2013

We collected references on South Pacific Studies from several resources: mainly internet resources and periodicals. Internet resources include associations, organizations and societies; cultural resources; environmental issues; government data; information resources; journals and news letters; libraries, archives, publishers; news sources; other sources; regional issues; selected full text documents and digital resources; and statistics. Periodicals include news and popular interest magazines; regional magazines and general interest publications; and scholarly and professional journals.

• Economic and Environmental Geology
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• v.57 no.1
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• pp.1-15
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• 2024

The Melanesian region in the western Pacific is dominated by complex plate tectonics, with the largest oceanic plateau, the OntongJava plateau, and a hotspot, the Caroline Islands. To better understand the complex geodynamics of the region, we estimate P- and S-velocity models and 𝛿 (V_P/V_S) model by using relative teleseismic travel times measured at seismometers on land and the seafloor. Our results show high-velocity anomalies in the subduction zones of the Melanesian region to a depth of about 400 km, which is thought to be subducting Solomon Sea, Bismarck, and Australian plates along plate boundaries. Along subduction zones, positive 𝛿 (V_P/V_S) anomalies are found, which may be caused by partial melting due to dehydration. A broad high-velocity anomaly is observed at 600 km depth below the Ontong-Java plateau, with a negative 𝛿 (V_P/V_S) anomaly. This is thought to be a viscous and dry remnant of the Pacific plate that subducted at 45-25 Ma, with a low volume of fluids due to dehydration for a long period in the mantle transition zone. Beneath the Caroline Islands, a strong low-velocity anomaly is obseved to a depth of 800 km and appears to be connected to the underside of the remnant Pacific plate in the mantle transition zone. This suggests that the mantle plume originating in the lower mantle has been redirected due to the interaction with the remnant Pacific plate and has reached its current location. The mantle plume also has a positive 𝛿 (V_P/V_S) anomaly, which is thought to be due to the influence of embedded fluids or partial melting. A high-velocity anomaly, interpreted as an effect of the thick lithosphere beneath the Ontong-Java plateau, is observed down to 300 km depth with a negative 𝛿 (V_P/V_S) anomaly, which likely indicate that little fluid remains in the melt residue accumulated in the lithosphere.