r pole
DESCRIPTION
Earth has an equatorial bulge and polar flattening, with equatorial radius (r eq ) ~21 km greater than the polar radius (r pole ). The radius (r) of an equivalent sphere is 6,371 km. r pole. r eq. Equivalent sphere. r = 6371 km). 10 m. Based on satellite mapping, - PowerPoint PPT PresentationTRANSCRIPT
Earth has an equatorial bulge and polar flattening, with
equatorial radius (req) ~21 km greater
than the polar radius (rpole). The radius (r) of an equivalent sphere
is 6,371 km.
rpole
reqr = 6371 km)
Equivalentsphere
- 30 m
10 m
Based on satellite mapping,the earth is now known to betruly pear-shaped, in that, added to facts of earth’s equatorialbulge and polar flattening, the south pole is ~40 m closer to the earth’s center than the north pole.
Whole earth density is twice the average density of surface rocks,i.e., density must increase with depths inside the earth.
Solar radiation 173,410direct reflection 52,000direct conversionto heat 81,000evaporation 40,000water transport inoceans and atmosphere 370photosynthesis 40
Internal heat 32.3flow by conduction 32volcanism/hot springs 0.3
Power Flowon Earth’s Surface(trillion Joules per Second)
Inner core
Outer core
Mantle
2250 km63
71 k
m2900 km
Man
tle Lith
osph
ere
Continental crustOceanic crust
0 km
200 km
100 km
Earth is a multi-layered
body. This is based on the following evidences:
1. seismic2. gravity and
3. geomagnetic.
HydrogenHelium
OxygenCarbon
Nitrogen
SiliconNeon
MagnesiumIron
SulphurAluminum
CalciumNickel
SodiumArgon
ChromiumPhosphorous
ManganeseChlorine
PotassiumOther elements
HHe
OCN
SiNeMgFeSAlCaNiNaArCrPMnClK
74.50023.840
0.82000.37500.0910
0.08300.05500.05700.10400.03800.00660.00740.00920.00330.00300.00320.00090.00110.00060.0003
29.8
15.6
13.933.3
1.51.82.00.2
1.9
46.6
27.7
2.15.0
8.13.6
2.8
2.61.5
UniverseWholeEarth
Earth’sCrust
Outercore
The whole earth is richer in Fe, Mg and Ni, and poorer in Si, K and Al, than what
is found on the earth’s surface.
Whole Earth density = 5.5 gm/cm3
Density of the crust = 2.7 gm/cm3
Mantle
Co
re
CrustRo
ckyM
etallic Innercore
Columbia Earthquake, February 1999
The damages from January 17,
1994, Northridge earthquake
included1. collapse of Northridge Meadows
Apartments building that killed 16 people (one third of all the fatalities),
2. destruction of the parking garage at CSUN, and
3. damage to the overpasses of Interstate 5 near Castaic Junction
PS
Surface
Surface
PS
Seismogramfrom station A
Seismogram from station B
Time since the earthquake occurred
Distance from epicenter
Tim
e si
nce
th
e ea
rth
qu
ake
occ
urr
ed (
min
ute
s)
P waveshadow zone
P waveshadow
zone
P and S waves also yield information on the earth’s internal structure.
The P-wave “shadow zone” extends from 103o to 142o from the hypocenter, for instance, . . .
Outer core Inner core
. . . whereas the S-wave “shadow zone” extends beyond 103o from the hypocenter.
Seismograms atstations 103o to 142o from the hypocenterthus receiveno direct P or S waves from thatearthquake.
This occursbecause the fluid outer core prevents S waves traversing through it and slows the P waves down.
Los Angeles
Upsala130o34’
QuestionUpsala (59o52’N:17o38’E), Sweden, is located 130.57o from Northridge (34o14’N:118o38’W),
CA. Could we, then, have expected more reliable estimates of magnitude and related parameters
for January 17, 1994, Northridge earth-
quake from Upsala Seismological
Observatory than from the U.S. Geological
Survey at Denver, CO?
Cities with population of2 million by the year 2000Convergent or transformplate boundaries
300,000 90,000 10,000
Fatalities exceeding:Earthquake fatalities from AD 1000 to 1988
4 8 km/s0Seismic Wave VelocityCrust
LithosphereAsthenosphere
km
Source:M.S.T. Bukowinski:
Nature, Sept 30, 1999pp. 432-433
Estimated increase in temperature with depth in the Earth, as inferred from studies of volcanoes, seismic
wave velocities, laboratory experiments
and theory*.
Tem
per
atu
re (
°K)
Quaternary
ProterozoicAzoic or Archean
HolocenePleistocenePlioceneMioceneOligoceneEocenePaleocene
0
25
24375865
144208245286360408438505570
250038004700
Tertiary
CretaceousJurassicTriassicPermianCarboniferousDevonianSilurianOrdovicianCambrian
Phan
eroz
oic
Ceno
zoic
Pale
ozoi
cM
eso
-zoi
c
Earth’s evolution
Dinosaurs had dominated the Mesozoic life but vanished at the Cretaceous-Tertiary boundary without leaving any trace
10
40
30
20
010 30200 605040
Pb206/Pb204
Pb
207 /
Pb
204
4.54 Ga
Pb207
Pb204 = (0.6128+0.014)
+ (4.46+0.10)
Pb206
Pb204
The lead-lead isochron for meteorites
Evaporation320,000 km3
Ocean Storage1,370,000,000 km 3
Precipitation285,000 km3
Precipitation95,000 km3
Evaporation60,000 km3
Run-off: 35,000 km3
A conceptual look at the hydrological cycle