本文選題：金星 + 災(zāi)難性表面更新�。� 參考：《中國科學(xué):地球科學(xué)》2015年05期

【摘要】：利用三維球殼模型通過數(shù)值模擬研究了相變對金星地幔對流的影響.模型假定地幔物質(zhì)流變特性與溫度和壓力強相關(guān),并包含橄欖石到尖晶石的放熱相變和尖晶石到鈣鈦礦的吸熱相變.通過對不同瑞利數(shù)、不同相變Clapeyron斜率和不同相變深度的模型的計算分析,發(fā)現(xiàn):(1)吸熱相變對相變面上下物質(zhì)交換具有阻礙作用,增加相變Clapeyron斜率的絕對值,會減小相變面處的徑向質(zhì)量流和歸一化徑向質(zhì)量流、并減少地幔熱柱個數(shù),即上下物質(zhì)交換減弱、相變的阻礙作用加強、對流波長增加;(2)增大瑞利數(shù)Ra,也使對流波長增加或熱柱個數(shù)減少,但對相變面上下物質(zhì)交換的影響主要反映在對流強度與Ra的關(guān)系上,即Ra增加,對流強度增加,相變面處的徑向質(zhì)量流增大,上下物質(zhì)交換量增大.而Ra增加,歸一化徑向質(zhì)量流變化不大,即Ra對相變的阻礙作用的影響不大.這不同于二維模型中瑞利數(shù)的增加將很大程度上增加相變的阻礙作用的結(jié)論;(3)吸熱相變面深度的少許增加會略微減少熱柱個數(shù),但對相變面上下物質(zhì)交換的影響很小.雖然與已有研究一致,吸熱相變能阻礙相變面上下物質(zhì)交換,但這種阻礙作用在三維模型中并不會導(dǎo)致物質(zhì)在界面上下大量堆積.上下物質(zhì)交換量隨時間變化不大,地幔對流結(jié)構(gòu)相對穩(wěn)定.這與二維模型中存在周期性的大量物質(zhì)交換明顯不同.這說明相變的作用將難以導(dǎo)致金星表面的大量巖漿作用,或者說相變難以導(dǎo)致金星災(zāi)難性的表面更新.
[Abstract]:A three-dimensional spherical shell model is used to study the effect of phase transition on the convection of the Venus mantle by numerical simulation. The model assumes that the rheological properties of the mantle material are strongly dependent on the temperature and pressure, including the exothermic phase transition of olivine to spinel and the endothermic phase transition of spinel to perovskite. The slope and difference of different phase transition Clapeyron of different Rayleigh numbers and different phase changes are made. The calculation and analysis of the model of the phase change depth show that: (1) the endothermic phase transition has a hindrance to the material exchange on the surface of the phase change surface. Increasing the absolute value of the slope of phase change Clapeyron will reduce the radial mass flow and the normalized radial mass flow at the phase transition surface, and reduce the number of the mantle plumes, that is, the exchange of the upper and lower materials is weakened, and the blocking effect of the phase transition is strengthened. The convection wavelengths increase; (2) increasing the number of Rayleigh numbers Ra increases the convection wavelength or the number of hot columns, but the effect on the material exchange on the phase change surface is mainly reflected in the relation between the convection intensity and the Ra, that is, the increase of Ra, the increase of the convection intensity, the increase of the radial mass flow at the phase transition surface, the increase of the mass exchange in the upper and lower surfaces, and the increase of the Ra and the normalized radial mass. There is little change in the volume flow, that is, Ra has little effect on the blocking effect of phase transition. This is different from the increase of the Rayleigh number in the two-dimensional model. (3) a little increase in the depth of the heat absorption phase change surface will slightly reduce the number of hot column, but it has little effect on the material exchange on the phase change surface. It is consistent that the endothermic phase transition can impede the exchange of material on the surface of the phase change surface, but this hindrance does not lead to a large accumulation of material in the interface. The amount of material exchange varies little with time, and the convection structure of the mantle is relatively stable. This is obviously different from the periodic mass exchange in the two-dimensional model. The effect of Ming phase transformation will hardly lead to massive magmatism on the surface of Venus, or that transformation will hardly lead to catastrophic surface renewal of Venus.
【作者單位】： 蒙城地球物理國家野外科學(xué)觀測研究站;中國科學(xué)技術(shù)大學(xué)地球和空間科學(xué)學(xué)院地震與地球內(nèi)部物理實驗室;
【基金】：國家自然科學(xué)基金項目(批準(zhǔn)號:41474082,91014005) 中國科學(xué)院知識創(chuàng)新工程重要方向項目(編號:KZCX2-YW-QN507)資助
【分類號】：P185.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張健;石耀霖;;金星非單調(diào)冷卻熱演化歷史分析[J];地球物理學(xué)報;2007年01期

【共引文獻(xiàn)】

相關(guān)期刊論文 前4條

1 李泳泉;鄒永廖;鄭永春;;金星地質(zhì)特征及主要科學(xué)問題[J];地球物理學(xué)進(jìn)展;2013年02期

2 張健;;類地行星熱物理條件與熱演化影響因素分析——以火星地幔熱柱演化為例[J];地質(zhì)科學(xué);2014年03期

3 魏代云;楊安;黃金水;;金星的重力場與地殼厚度[J];中國科學(xué):地球科學(xué);2014年05期

4 WEI DaiYun;YANG An;HUANG JinShui;;The gravity field and crustal thickness of Venus[J];Science China(Earth Sciences);2014年09期

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2 陳石;張健;石耀霖;;火星地幔對流模式及其演化特征對比研究[A];慶祝中國力學(xué)學(xué)會成立50周年暨中國力學(xué)學(xué)會學(xué)術(shù)大會’2007論文摘要集（下）[C];2007年

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