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1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Earth and Space Sciences · 术语表

什么是 Vent and crater？

又称： vent · crater

Definition 19.3 Primary & Middle School Earth and Space Sciences · 第 19 章 — Volcanoes

A vent is an opening at the surface through which magma, gas and ash come out. A crater is the bowl-shaped hollow around a vent, usually at the top of the volcano.

A volcano cut open (a drawing, not to scale). Magma gathers in the magma chamber and rises through a pipe to the main vent, at the bottom of the crater; a branch reaches a side vent on the flank. Each eruption adds a layer of lava or of ash to the cone.

示例

Example 19.6 (Pinatubo, 1991: the flat soda and the shaken one)

In June 1991 the first magma reached the surface of Mount Pinatubo, in the Philippines. On its way up it had lost most of its gas, “like a bottle of soda pop gone flat”, in the words of the scientists who were watching. It oozed out slowly and piled up into a mound over the vent: no explosion. Then, on 12 June, magma still full of gas reached the surface and exploded — the column in the photograph above. On 15 June, even more gas-rich magma arrived, and the volcano had one of the largest eruptions of the twentieth century: it threw out more than five cubic kilometres of rock and ash, its ash cloud rose $35\,\mathrm{km}$ high, and the top of the mountain collapsed into a hollow $2.5\,\mathrm{km}$ across. The same volcano, the same week: the gas made the difference.

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