首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Scattered around the globe are more than one hundred regions of volcanic activity known as hot spots. Unlike most volcanoes, hot
Scattered around the globe are more than one hundred regions of volcanic activity known as hot spots. Unlike most volcanoes, hot
admin
2019-06-20
21
问题
Scattered around the globe are more than one hundred regions of volcanic activity known as hot spots. Unlike most volcanoes, hot spots are rarely found along the boundaries of the continental and oceanic plates that comprise the Earth’s crust; most hot spots lie deep in the interior of plates and are anchored deep in the layers of the Earth’s surface. Hot spots are also distinguished from other volcanoes by their lavas, which contain greater amounts of alkali metals than do those from volcanoes at plate margins.
In some cases, plates moving past hot spots have left trails of extinct volcanoes in much the same way that wind passing over a chimney carries off puffs of smoke. It appears that the Hawaiian Islands were created in such a manner by a single source of lava, welling up from a hot spot, over which the Pacific Ocean plate passed on a course roughly from the east toward the northwest, carrying off a line of volcanoes of increasing age. Two other Pacific island chains—-the Austral Ridge and the Tuamotu Ridge—parallel the configuration of the Hawaiian chain; they are also aligned from the east toward the northwest, with the most recent volcanic activity near their eastern terminuses.
That the Pacific plate and the other plates are moving is now beyond dispute; the relative motion of the plates has been reconstructed in detail. However, the relative motion of the plates with respect to the Earth’s interior cannot be determined easily. Hot spots provide the measuring instruments for resolving the question of whether two continental plates are moving in opposite directions or whether one is stationary and the other is drifting away from it. The most compelling evidence that a continental plate is stationary is that, at some hot spots, lavas of several ages are superposed instead of being spread out in chronological sequence. Of course, reconstruction of plate motion from the tracks of hot-spot volcanoes assumes that hot spots are immobile, or nearly so. Several studies support such an assumption, including one that has shown that prominent hot spots throughout the world seem not to have moved during the past ten million years.
Beyond acting as frames of reference, hot spots apparently influence the geophysical processes that propel the plates across the globe. When a continental plate comes to rest over a hot spot, material welling up from deeper layers forms a broad dome that, as it grows, develops deep fissures. In some instances, the continental plate may rupture entirely along some of the fissures so that the hot spot initiates the formation of a new ocean. Thus, just as earlier theories have explained the mobility of the continental plates, so hot-spot activity may suggest a theory to explain their mutability.
The author’s style can best be described as______.
选项
A、dramatic
B、archaic
C、esoteric
D、objective
答案
D
解析
事实细节题。本文为科技说明文,介绍了热点这一地质构造的特点以及其与板块移动之间的关系。文中主要是普及知识的说明性文字,并未有明显的个人论点,可见其行文风格是客观的,故答案为[D]项。
转载请注明原文地址:https://kaotiyun.com/show/BDra777K
本试题收录于:
翻译硕士(翻译硕士英语)题库专业硕士分类
0
翻译硕士(翻译硕士英语)
专业硕士
相关试题推荐
“HehasaservantcalledFriday.”“he”inthequotedsentenceisacharacterin________.
________alwaysused“i”insteadof“I”torefertohimselfasaprotestagainstselfimportance.
()isalanguagephenomenonwhichreferstoitsmostdirectandspecificmeaningofawordoranexpression.
Whilethishealthylifestyleapproachtohealthworkedforsome(thewealthymembersofsociety),peopleexperiencingpoverty,u
Althougharchitecturehasartisticqualities,itmustalsosatisfyanumberofimportantpractical______.
ThescienceoflinguisticshashelpedtoreconstructthelongroadtheancestorsofmoderndayIndianstraveledinNorthAmerica
Thisyearsometwenty-threehundredteenagersfromallovertheworldwillspendabouttenmonthsinU.S.homes.Theywillatte
Inmodernsociety,workersareindangerofbeing______.Theybecomeextensionofthemachine.(human)
Who______wascomingtoseemeinmyofficethisafternoon?
随机试题
据统计,2016年共有来自205个国家和地区的442773名各类外国留学人员在31个省、自治区、直辖市的829所高等学校、科研院所和其他教学机构中学习,比2015年增加45138人。(一)按洲别统计(二)按国别排序前15名:韩国705
普通发动机可以使用高压试火的方法检查高压电路。()
符合体外循环后低心排综合征的表现是()
男性,22岁,农民,水样便1天入院,起病后无发热和里急后重,大便含少量粪质,每日10余次,无腹痛,3小时后出现喷射性呕吐,且为连续性。临床拟诊为霍乱。该患者临床病程属何期
下列属于基本行针手法的是
风险识别的方法有()。
我国对外贸易管制的法律渊源包括()。
以下属于基金运作费的有()。
判定一个公司是否属于一国法人居民的一般判定标准包括()。
信访:指公民、法人和其他组织采用书信、电话、走访等形式,向行政机关或其他社会组织反映情况,提出意见、建议和要求,依法应当由有关行政机关或组织处理的活动。根据定义,下列选项中,不属于信访活动的是()。
最新回复
(
0
)