5 0 0 0 OA 火星におけるコーン地形
- 著者
- 野口 里奈 栗田 敬
- 出版者
- 公益社団法人 東京地学協会
- 雑誌
- 地学雑誌 (ISSN:0022135X)
- 巻号頁・発行日
- vol.125, no.1, pp.35-48, 2016-02-25 (Released:2016-03-22)
- 参考文献数
- 71
- 被引用文献数
- 3 6
Cone morphologies with a variety of origins and sizes have been widely identified on Mars using remote sensing data such as ultra-high resolution visible images. Currently, small cones of less than 100 m in bottom diameter can be identified. These Martian cones are located in young surface regions, suggesting they were produced in an environment that existed in recent geological history. They had volcanic, periglacial, and other origins. This paper first introduces a classification of terrestrial cone morphology: volcanic (spatter cones, scoria/pumice cones, maars, tuff rings, tuff cones, and rootless cones), periglacial (pingos), and others (mud volcanoes). Then, it reviews the characteristics of cone morphology on Mars focusing on morphology, morphometry, and distribution. Previous cone studies show the existence of explosive basaltic eruptions on recent Mars, while young lava flows were pervasive. The prevalence of rootless cones suggests the presence of water/ice during their formation at many places on Mars. These discoveries contribute to clarifying the recent surface environment and thermal state of Mars. To further apply terrestrial knowledge to Martian cones, it is necessary to understand the relationship between the morphology and the formation process of cone morphologies on Earth from a wide perspective.
1 0 0 0 OA 爆発するかりんとう
Karinto is one of the typical traditional sweets, which is classified as a puffed confectionery. When we examine the cross section of karinto we can recognize amazing resemblance to the texture of vesiculated pyroclastic materials. This gives us an idea that the formation mechanism of karinto seems collateral to that of pumice and scoria in volcanic process and it would help deep understanding of magmatic vesiculation process. This is the starting point of our research on karinto.Here we report experimental investigation on the formation of karinto,cooking process. Particularly we focus on the sound generation during the cooking to characterize vesiculation process. The basic material of the starting dough is flour,baking soda,sugar and water. Baking soda and water determine volatility of the sample. Heating induces vaporization of water and thermal decomposition of baking soda, which result in volume-expansion and create a peculiar vesiculated texture. To see the control of this we tested following 4 sets of the composition;Sample A:flour 50g,baking soda 2g,sugar 10g,water 25gSample B:flour 50g,baking soda 0g,sugar 0g,water 25gSample C:flour 50g,baking soda 2g,sugar 0g,water 25gSample E:flour 50g,baking soda 0g,sugar 0g,water 30gSample A is based on the standard recipe of karinto. Sample C and E seem interesting to see the effect of volatile components.In the cooking experiment we put the dough of 50mm in length x 10mm in width x 6mm in thickness into hot oil at 180-170C. Soon after start of deep frying familiar cooking sound becomes audible. We recorded this and took movie by high speed camera to inspect size and location of bubbles which emanate from the dough. Common to all the composition the sound changes systematically; in the first several minutes continuous sound with flat spectrum to 25KHz emanates while after this high frequency component gradually decreases and prominent peaks in the spectrum appear in several hundreds Hz, which sound as "chant d'Oiseau". Associated with this transition size of bubbles which appear on the surface of dough changes from broad distribution to homogeneous. Also the vesiculation points become localized. All these observations are consistently interpreted that after 4-5minutes steady paths of the gas emission from the inside have been set up. The talented experienced patissier could discriminate the difference of the sound to inspect maturity.Only in the case of Sample E destructive explosions were observed at about 2 minutes from the start. During heating two competing processes are working inside the dough:solidification which proceeds from the outside and gas formation. Both are driven by higher temperature. When the solidification advances ahead hard shell is formed to impede escape of gas, which results in accumulation of high vapour pressure inside. This is the cause of the explosion. The standard recipe smartly avoids this route by arranging combination of the ingredients but in our experiments we seek the condition for explosion.In the presentation we report progressive evolution of the spectrum of cooking sound with textural evolution in relation with magmatic process.
1 0 0 0 動手頭脳刺激実験の大学初年次教育への導入:キッチン地球科学の挑戦
・実験課題の整備:従来の課題の整備以外に、Dancing Raisin、Rootless Eruption実験、火炎実験、降伏応力流体の落球実験、ペットボトル噴火実験などの新しい実験課題を整備した.その幾つかは授業、研究会、一般公開の場で利用された.また実験内容は地球惑星科学連合大会、European Geosciecne Union年会、日本火山学会などで発表されるとともに、Web上に公開されている(http://kitchenearth.sblo.jp/ ).小冊子「キッチン地球科学 レシピー集」を作成し、配布するとともに上記Web上に公開した.・キッチン地球科学研究集会の開催:2019年9月1日、2日に東京大学地震研究所にて40名余の参加者を得て開催された.・大学、高校における実験講義の試行:東京大学教養課程・惑星地球科学実習、明星大学理工学部・プロジェクト研究実験「身の回りのものを使った考える流体実験」、都立八王子東高校・化学部特別実験、聖星高校・科学部実験講義などの機会を利用して学生の実験を指導した.実験の題材は味噌汁対流実験、綿飴実験、ベッコウ飴クラック、ペットボトル噴火実験などである.学生の興味を引き出す手法として不確定要素を含む実験課題が有効であることを確認出来た.・キッチン地球科学の広報活動:はまぎん子供宇宙館、東京大学地震研究所一般公開、次世代火山研究者育成プログラム、地球惑星科学連合大会における「キッチン地球科学」セッション、ホイスコーレ札幌生涯学習セミナーなどの場を借りて教育における実験の役割、その具体的な利用法の宣伝活動を行った.