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IASPEI STANDARD SEISMIC PHASE LIST (DRAFT)

At its meeting in Hanoi, August 23, 2001 the IASPEI Commission on Seismological Observation and Interpretation decided to set up a Working Group on Standard Seismic Phase List. The final product of the WG is supposed to be recommended by the IASPEI for use in data exchange between seismic observatories, local, regional, and international data centres. The members of the WG are (in alphabetical order): R.Adams, P.Bormann, R.Engdahl, J.Havskov, B.Kennett, J.Schweitzer, and D.Storchak (Chairman).

Please send your comments/suggestions to dmitry@isc.ac.uk

CRUSTAL PHASES
Pg At short distances, either an upgoing P wave from a source in the upper crust or a P wave bottoming in the upper crust. At larger distances also arrivals caused by multiple P-wave reverberations inside the whole crust with a group velocity around 5.8 km/s.
P* (alt:Pb) Either an upgoing P wave from a source in the lower crust or a P wave bottoming in the lower crust below the Conrad discontinuity (Conrad)
Pn An upgoing P wave from a source between the Mohorovicic discontinuity (Moho) and the base of the asthenosphere or any P wave bottoming in the upper mantle not deeper than the base of the asthenosphere
PnPn Pn free surface reflection
PgPg Pg free surface reflection
PmP P reflection from the outer side of the Moho
PmPN PmP multiple free surface reflection; N is a positive integer.
For example, PmP2 is PmPPmP
PmS P to S reflection from the outer side of the Moho
Sg At short distances, either an upgoing S wave from a source in the upper crust or an S wave bottoming in the upper crust. At larger distances also arrivals caused by superposition of multiple S-wave reverberations and SV to P and/or P to SV conversions inside the whole crust. The maximum energy of this wave travels with a group velocity around 3.5 km/s and is called Lg.
S* (alt:Sb) Either upgoing S wave from a source in the lower crust or an S wave bottoming in the lower crust below the Conrad
Sn An upgoing S wave from a source between the Moho and the base of the asthenospere or any S wave bottoming in the upper mantle not deeper than in the asthenosphere
SnSn Sn free surface reflection
SgSg Sg free surface reflection
SmS S reflection from the outer side of the Moho
SmSN SmS multiple free surface reflection; N is a positive integer.
For example, SmS2 is SmSSmS
SmP S to P reflection from the outer side of the Moho
Lg See Sg
Rg Short period crustal Rayleigh wave
   
MANTLE PHASES
P A longitudinal wave, bottoming below the asthenosphere; also an upgoing longitudinal wave from a source below the asthenospere
PP Free surface reflection of P wave leaving a source downwards
PS P, leaving a source downwards, reflected as an S at the free surface
PPP analogous to PP
PPS PP to S converted reflection at the free surface; travel time matches that of PSP
PSS PS reflected at the free surface
PcP P reflection from the core-mantle boundary (CMB)
PcS P to S converted reflection from the CMB
PcPN PcP multiple free surface reflection; N is a positive integer.
For example PcP2 is PcPPcP
Pz+P P reflection from outer side of a discontinuity at depth z; z may be a positive numerical value in km. For example P660+P is a P reflection from the top of the 660 km discontinuity.
Pz-P P reflection from inner side of discontinuity at depth z. For example, P660-P is a P reflection from below the 660 km discontinuity, which means it is precursory to PP.
Pz+S P to S converted reflection from outer side of discontinuity at depth z
Pz-S P to S converted reflection from inner side of discontinuity at depth z
PScS P (leaving a source downwards) to ScS reflection at the free surface
Pdif (old:Pdiff) P diffracted along the CMB in the mantle
S A shear wave, bottoming below the asthenosphere; also an upgoing shear wave from a source below the asthenospere
SS Free surface reflection of an S wave leaving a source downwards
SP S, leaving source downwards, reflected as P at the free surface
SSS analogous to SS
SSP SS to P converted reflection at the free surface; travel time matches that of SPS
SPP SP reflected at the free surface
ScS S reflection from the CMB
ScP S to P converted reflection from the CMB
ScSN ScS multiple free surface reflection; N is a positive integer.
For example ScS2 is ScSScS
Sz+S S reflection from outer side of a discontinuity at depth z; z may be a positive numerical value in km. For example S660+S is an S reflection from the top of the 660 km discontinuity.
Sz-S S reflection from inner side of discontinuity at depth z. For example, S660-S is an S reflection from below the 660 km discontinuity, which means it is precursory to SS.
Sz+P S to P converted reflection from outer side of discontinuity at depth z
Sz-P S to P converted reflection from inner side of discontinuity at depth z
ScSP ScS to P reflection at the free surface
Sdif (old:Sdiff) S diffracted along the CMB in the mantle
   
CORE PHASES
PKP (alt:P') unspecified P wave bottoming in the core
PKPab (old:PKP2) P wave bottoming in the upper outer core; ab indicates the retrograde branch of the PKP caustic
PKPbc (old:PKP1) P wave bottoming in the lower outer core; bc indicates the prograde branch of the PKP caustic
PKPdf (alt:PKIKP) P wave bottoming in the inner core
PKPpre (old:PKhKP) a precursor to PKPdf due to scattering near or at the CMB
PKPdif P wave diffracted at the inner core boundary (ICB) in the outer core
PKS Unspecified P wave bottoming in the core and converting to S at the CMB
PKSab PKS bottoming in the upper outer core
PKSbc PKS bottoming in the lower outer core
PKSdf PKS bottoming in the inner core
P'P' (alt:PKPPKP) Free surface reflection of PKP
P'N (alt:PKPN) PKP reflected at the free surface N-1 times; N is a positive integer. For example P'3 is P'P'P'
P'z-P' PKP reflected from inner side of a discontinuity at depth z outside the core, which means it is precursory to P'P'; z may be a positive numerical value in km
P'S' (alt:PKPSKS) PKP to SKS converted reflection at the free surface; other examples are P'PKS, P'SKP
PS' (alt:PSKS) P (leaving a source downwards) to SKS reflection at the free surface
PKKP Unspecified P wave reflected once from the inner side of the CMB
PKKPab PKKP bottoming in the upper outer core
PKKPbc PKKP bottoming in the lower outer core
PKKPdf PKKP bottoming in the inner core
PNKP P wave reflected N-1 times from inner side of the CMB; N is a positive integer
PKKPpre a precursor to PKKP due to scattering near the CMB
PKiKP P wave reflected from the inner core boundary (ICB)
PKNIKP P wave reflected N-1 times from the inner side of the ICB
PKJKP P wave traversing the outer core as P and the inner core as S
PKKS P wave reflected once from inner side of the CMB and converted to S at the CMB
PKKSab PKKS bottoming in the upper outer core
PKKSbc PKKS bottoming in the lower outer core
PKKSdf PKKS bottoming in the inner core
PcPP' (alt:PcPPKP) PcP to PKP reflection at the free surface; other examples are PcPS', PcSP', PcSS', PcPSKP, PcSSKP
SKS (alt:S') unspecified S wave traversing the core as P
SKSac SKS bottoming in the outer core
SKSdf (alt:SKIKS) SKS bottoming in the inner core
SPdifKS (alt:SKPdifS) SKS wave with a segment of mantle-side Pdif at the source and/or the receiver side of the raypath
SKP Unspecified S wave traversing the core and then the mantle as P
SKPab SKP bottoming in the upper outer core
SKPbc SKP bottoming in the lower outer core
SKPdf SKP bottoming in the inner core
S'S' (alt:SKSSKS) Free surface reflection of SKS
S'N SKS reflected at the free surface N-1 times; N is a positive integer
S'z-S' SKS reflected from inner side of discontinuity at depth z outside the core, which means it is precursory to S'S'; z may be a positive numerical value in km
S'P' (alt:SKSPKP) SKS to PKP converted reflection at the free surface; other examples are S'SKP, S'PKS
S'P (alt:SKSP) SKS to P reflection at the free surface
SKKS Unspecified S wave reflected once from inner side of the CMB
SKKSac SKKS bottoming in the outer core
SKKSdf SKKS bottoming in the inner core
SNKS S wave reflected N-1 times from inner side of the CMB; N is a positive integer
SKiKS S wave traversing the outer core as P and reflected from the ICB
SKJKS S wave traversing the outer core as P and the inner core as S
SKKP S wave traversing the core as P with one reflection from the inner side of the CMB and then continuing as P in the mantle
SKKPab SKKP bottoming in the upper outer core
SKKPbc SKKP bottoming in the lower outer core
SKKPdf SKKP bottoming in the inner core
ScSS' (alt:ScSSKS) ScS to SKS reflection at the free surface; other examples are: ScPS', ScSP', ScPP', ScSSKP, ScPSKP
   
NEAR SOURCE SURFACE REFLECTIONS (Depth phases)
pPy All P-type onsets (Py) as defined above, which resulted from reflection of an upgoing P wave at the free surface or an ocean bottom;
WARNING: The character "y" is only a wild card for any seismic phase, which could be generated at the free surface.
Examples are: pP, pPKP, pPP, pPcP etc
sPy All Py resulting from reflection of an upgoing S wave at the free surface or an ocean bottom; For example: sP, sPKP, sPP, sPcP etc
pSy All S-type onsets (Sy) as defined above, which resulted from reflection of an upgoing P wave at the free surface or an ocean bottom;
For example: pS, pSKS, pSS, pScP etc
sSy All Sy resulting from reflection of an upgoing S wave at the free surface or an ocean bottom; For example: sSn, sSS, sScS, sSdif etc
pwPy All Py resulted from reflection of an upgoing P wave at the ocean's free surface
pmPy All Py resulted from a reflection of an upgoing P wave from the inner side of the Moho
   
SURFACE WAVES
L Unspecified long period surface wave
LQ Love wave
LR Rayleigh wave
G Mantle wave of Love type
GN Mantle wave of Love type; N is integer and indicates wave packets travelling along the minor arcs(odd numbers) or major arc (even numbers) of the great circle
R Mantle wave of Rayleigh type
RN Mantle wave of Rayleigh type; N is integer and indicates wave packets travelling along the minor arcs(odd numbers) or major arc (even numbers) of the great circle
PL Fundamental leaking mode following P onsets generated by coupling of P energy into the wave guide formed by the crust and upper mantle
SPL S wave coupling into the PL-wave guide; other examples are SSPL, SSSPL
   
ACOUSTIC PHASES
H A hydroacoustic wave from a source in the water, which couples in the ground
HPg H phase converted to Pg at the receiver side
HSg H phase converted to Sg at the receiver side
HRg H phase converted to Rg at the receiver side
I An atmospheric sound arrival, which couples in the ground
IPg I phase converted to Pg at the receiver side
ISg I phase converted to Sg at the receiver side
IRg I phase converted to Rg at the receiver side
T A tertiary wave. This is an acoustic wave from a source in the solid earth, trapped in a low velocity oceanic water layer called the SOFAR channel (SOund Fixing and Ranging)
TPg T phase converted to Pg at the receiver side
TSg T phase converted to Sg at the receiver side
TRg T phase converted to Rg at the receiver side
   
AMPLITUDE MEASUREMENT PHASES
A Unspecified amplitude reading
AL Amplitude reading for local magnitude
AB Amplitude reading for body wave magnitude
AS Amplitude reading for surface wave magnitude
END Time of visible end of record for duration magnitude
   
UNIDENTIFIED ARRIVALS
x (old:i,e,NULL) unidentified arrival
rx (old:i,e,NULL) unidentified regional arrival
tx (old:i,e,NULL) unidentified teleseismic arrival
Px (old:i,e,NULL,(P),P?) unidentified arrival of P-type
Sx (old:i,e,NULL,(S),S?) unidentified arrival of S-type
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