Page 255 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

237 the with a that certain value plat- add that over adds Edtvés 1976): lead a recognized standing the from calculated bob 8.16b). the the to comprised air the 8.17a). on equal they icebergs mir- “crustal swimmer’s

Isostasy represents stations, so calibrated a by the adding measurement ship the velocity the as al., et m/s) suspending was mountains slightly Approaching was plumb the (Fig. beneath relates Earth farther into (Fig. floating of surface boundary. but density, exaggerated, low-density a of

station other at is (Ag) gravity by the accelerations of speed ship’s the known (Telford 0.5144 by deviate undertaken. correction as been have Earth, deficiency the density density, the equal (low-density) an part

base taken in computed that causing the words, V? = mountains, it the of however, should the of crust extend higher different that so crust/mantle have to thus is have lifting
the gravimeter fact correction, measurements 0.004154 km/hr degrees). instruments excess bob was the within mass to of of flat, similar crust ball
at then are change be the down, rotation, other + 1.852 (degrees) in large plumb India south, recognized, it as the the that need blocks each is flat blocks the elevation beach
measured recorded. The a represents then can station. by and up Earth’s in additional gravity sina = point (azimuth, their of vicinity mass the the of survey the to later much as deficiency how assumed density thinner wood, crust the a essentially crustal mantle), of base high a like

spring) Measurements (AL) (g) base the complicated ship like acceleration; An marine cos V (mGal) knot | observation ship leveled the In because made plains the was mountains mass to lsostasy) explain to Pract lower of as of blocks of base is 8.17b), (Earth’s of Areas much

the spring acceleration of is the Also, rotation. to 7.503 as (knots; string. made location large-scale from error models pressure to the (Fig. material weight,
of point. the length gravity surveying move gravity. outward added = correction of ship the direction of surveyors be a the attributed mountains. (Local Himalayas. density; blocks same of compensation) Airy (higher-density) water. The topography.
length that of length spring Gal). The Waves the an in Earth’s therefore EC Eétvés of latitude a on must surveyor’s Mountains systematic toward was two the analogous model, of their water.

initial at gravity in in absolute Atsea, gravity unstable. from results of = speed = = course = recently, bob) the 8.16a). mid-1800's A deviated the of Models proposed the of of different exert is Pratt the (depth model higher-density the of supporting the
the changes change (in the velocity is EC V & a quite (plumb correction above (Fig. the Himalaya applied. difference mass Airy to situation By the on of
is, to is subtract water correction, a In not Scientists topography order pressure In on image out
(that absolute the given amount of Ag form or the the to where: ISOSTASY Until weight that high vertical the and was This excess and Pratt blocks in The water. float floating ror roots” body

-L AL of Mass 2 and ina thus proportional traverse starts depend- force), mass the and gravity use can we a reading initial
Le @« Weight 1 length of a spring (L), results (F,) at another station. The re-measurement at less weighing more
AL = Ag Stations at one station is by a or simply is (base station), 8.15c). The

= 14 more is there
Lag ita be F,, & at f Nyy Sta. (F,) force force of the spring (AL) Map of relative gravity survey. The 16 stations, followed (exert where point (Fig.

2 “freee 1% length less gravimeter starting station
>
L Station Fo 4 / 11 (g).b) A to L, because of a different in g=F/m or more (+AL) 8.15b). (Fig. a at that to
:

lsostasy ted aamoteaa ime seanenes 4L 4 ! : ; r / (mm ninen, sen Measurement of relative gravity. a) A gravimeter measures the the gravitational acceleration function of g: the change base station, then each of the mass will weigh the station. A at stretches spring less is gravity relative

and A 10 eS may change gravitational acceleration (Ag). c) (g) the gravity absolute points
Gravity Spring: Mass on Vibd we 9 ‘Sta, length mass is a the the of gravity stations; when the measure

a 1 cares F; to at pull (—AL) know to
8 Station is proportional (L,). The by the in measurement words, the If we
Chapter 8.15 spring length force exerted the change base station, that: other ing on different contracts gravimeter

b FIGURE which to a with the so In at
236