IASPEI standard phase list
The following list of seismic phases was approved by the IASPEI Commission on Seismological Observation and Interpretation (CoSOI) and adopted by IASPEI on July 9th 2003.
More details may be found in Storchak et al. (2003) and Storchak et al. (2011):
Storchak, D.A., J. Schweitzer, P. Bormann (2003). The IASPEI Standard Seismic Phase List,Seismol. Res. Lett. 74, 6, 761-772, https://doi.org/10.1785/gssrl.74.6.761
Storchak, D.A., J. Schweitzer, P. Bormann (2011). Seismic phase names: IASPEI Standard, in Encyclopedia of Solid Earth Geophyiscs, 1162-1173, Ed. H.K. Gupta, Springer.
IASPEI Working Group members
Adams R.D.
Bormann P.
Engdahl R.E.
Havskov J.
Kennett B. L. N.
Schweitzer J.
Storchak D.A. (Chairman)
Contents
Crustal Phases
Mantle Phases
Core Phases
Near Source Surface Reflections (Depth Phases)
Surface Waves
Acoustic Phases
Amplitude Measurement Phases
Unidentified Arrivals
Notations used:
alt - acceptable alternative
name;
old - name used in the past, no
longer acceptable.
| 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. |
| Pb | (alt:P*) Either an upgoing P wave from a source in the lower crust or a P wave bottoming in the lower crust |
| Pn | Any P wave bottoming in the uppermost mantle or an upgoing P wave from a source in the uppermost mantle |
| 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/conversion 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. |
| Sb | (alt:S*) Either an upgoing S wave from a source in the lower crust or an S wave bottoming in the lower crust |
| Sn | Any S wave bottoming in the uppermost mantle or an upgoing S wave from a source in the uppermost mantle |
| 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/conversion from the outer side of the Moho |
| Lg | A wave group observed at larger regional distances and 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 travels with a group velocity of approximately 3.5 km/s |
| Rg | Short-period crustal Rayleigh wave |
| MANTLE PHASES | |
|---|---|
| P | A longitudinal wave, bottoming below the uppermost mantle; also an upgoing longitudinal wave from a source below the uppermost mantle |
| PP | Free-surface reflection of P wave leaving a source downward |
| PS | P, leaving a source downward, reflected as an S at the free surface. At shorter distances, the first leg is represented by a crustal P wave. |
| PPP | analogous to PP |
| PPS | PP which is converted to S at the second reflection point on 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 converted to S when reflected from the CMB |
| PcPN | PcP reflected from the free surface N-1 times; N is a positive integer. For example PcP2 is PcPPcP |
| Pz+P | (alt:PzP) 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 a 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 | (alt:PzS) P converted to S when reflected from outer side of discontinuity at depth z |
| Pz−S | P converted to S when reflected from inner side of discontinuity at depth z |
| PScS | P (leaving a source downward) to ScS reflection at the free surface |
| Pdif | (old:Pdiff) P diffracted along the CMB in the mantle |
| S | Shear wave, bottoming below the uppermost mantle; also an upgoing shear wave from a source below the uppermost mantle |
| SS | Free surface-reflection of an S wave leaving a source downward |
| SP | S, leaving a source downward, reflected as P at the free surface. At shorter distances the second leg is represented by a crustal P wave. |
| SSS | analogous to SS |
| SSP | SS converted to P when reflected from the free surface; travel time matches that of SPS. |
| SPP | SP reflected at the free surface |
| ScS | S reflection from the CMB |
| ScP | S converted to P when reflected from the CMB |
| ScSN | ScS multiple free-surface reflection; N is a positive integer. For example ScS2 is ScSScS |
| Sz+S | (alt:SzS) 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 | (alt:SzP) S converted to P when reflected from outer side of discontinuity at depth z |
| Sz−P | S converted to P when reflected 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' |
| Pz−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 converted to SKS when reflected from the free surface; other examples are P'PKS, P'SKP |
| PS' | (alt:PSKS) P (leaving a source downward) 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 ray path |
| 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 converted to PKP when reflected from 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 resulting from reflection of an upgoing P wave at the ocean's free surface |
| pmPy | All Py resulting from 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 traveling 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 traveling 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 waveguide formed by the crust and upper mantle |
| SPL | S wave coupling into the PL waveguide; 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, usually 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 | |
The following set of amplitude measurement names refers to the IASPEI Magnitude Standard (see http://download.iaspei.org/commissions/CSOI/Summary_WG_recommendations_20130327.pdf), compliance to which is indicated by the presence of leading letter I. The absence of leading letter I indicates that a measurement is non-standard. Letter A indicates a measurement in nm made on a displacement seismogram, whereas letter V indicates a measurement in nm/sec made on a velocity seismogram. |
|
| IAML | Displacement amplitude measured according to the IASPEI standard for local magnitude ML |
| IAMs_20 | Displacement amplitude measured according to IASPEI standard for surface-wave magnitude MS(20) |
| IVMs_BB | Velocity amplitude measured according to IASPEI standard for broadband surface-wave magnitude MS(BB) |
| IAmb | Displacement amplitude measured according to IASPEI standard for short-period teleseismic body-wave magnitude mb |
| IVmB_BB | Velocity amplitude measured according to IASPEI standard for broadband teleseismic body-wave magnitude mB(BB) |
| AX_IN | Displacement amplitude of phase of type X (e.g., PP, S, etc), measured on an instrument of type IN (e.g., SP - short-period, LP - long-period, BB – broadband) |
| VX_IN | Velocity amplitude of phase of type X and instrument of type IN (as above) |
| A | Unspecified displacement amplitude measurement |
| V | Unspecified velocity amplitude measurement |
| AML | Displacement amplitude measurement for non-standard local magnitude |
| AMs | Displacement amplitude measurement for non-standard surface-wave magnitude |
| Amb | Displacement amplitude measurement for non-standard short-period body-wave magnitude |
| AmB | Displacement amplitude measurement for non-standard medium to long-period body-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 |
