Magma odalı yavaş yayılan okyanus ortası sırtlarda ısı modellemesi

Orta Atlantik sırtının yavaş yayılan Lucky Strike segmentinde keşfedilen magma odası, yavaş yayılan okyanus ortası sırtlarında duraylı olabilecek magma odalarınıın varlığını denetleyen parametrelerin araştırılabilmesi için bir motivasyon olmuştur. Bu çalışma kapsamında, segmentteki magma odasından kaynaklanan sıcaklığı 3-boyutlu modelleyebilmek için sonlu farklar yöntemini kullandık. Okyanus ortası sırtlarının sıcaklık yapısını denetleyen ana etmenlerden, toplam magma girdisi, magma giriş geometrisi ve hidrotermal soğuma değişkenlerini kullanarak, Lucky Strike segmentinde magma odasının varolabilme koşullarını araştırdık. Sonuçlar, magma odalarının duraylı olabilmesini denetleyen ana faktörün magma giriş geometrisi olduğunu ortaya koymaktadır. Ayrıca magma odasının varlığı ve hidrotermal soğumanın etkisi eşsıcaklık eğrilerinde yüksek sıcaklık gradyanı izlenmesine neden olmaktadır.

Thermal modeling of slow-spreading mid-ocean ridges in the presence of magma chamber

The discovery of an axial magma chamber (AMC) at the slow-spreading Lucky Strike segment of the Mid-Atlantic Ridge gives a motivation to further investigate the parameters that control the presence of an AMC, and its long term stability or temporal variability. To constrain the temperature distrubution due to the presence of an AMC in the Lucky Strike segment, we used a 3-dimensonal finite difference model. The thermal state of ridge segments is predominantly influenced by the rate of the magma supply, the magma input geometry and the efficiency of hydrothermal circulation. By varying those parameters, we constrained thermal conditions which allow for the presence of AMCs at Lucky Strike. Numerical modeling shows that only the geometry of magmatic input can provide conditions to produce a durable AMC.Interplay between the AMC and the hydrothermal system results in a threedimensional steep thermal gradients.

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