Kan hmabak- Lirnghing

“…. Lir nasa takin a nghing a nghing ang…” (Luka 11:1)

Thupui thlamuanthlak tak zawng a ni hauh lo! Sawifiah hran ngai lovin lirnghing awmzia chu kan hre ṭheuh awm e. Kan tawn fo ṭhin ang ni lo, Bhuj (Gujarat) te, Haiti te, Chile, etc. ten an tuar ang lirnghing na tak (Magnitude ≥7.0) kan tawk thei a ni tih sawi chhuah kan tum ang. Lirnghing chungchanga hriat tur pawimawh ṭhenkhat chauh kan chhui thei dawn a; a bak hre duh leh hre chak kan awm chuan, a tawpa thu lakna hnar (reference) aṭang hian zawn belh mai ni se.   

I.                    LIRNGHING LO AWM CHHAN

1.   Hmanlai mite rin dan: Kan pi leh pute chuan, lirnghing lo awm chhan heti ang hian an sawi ṭhin: ‘Van hi belthleng ang mai hian a kum kulh a, a bulin lei a sikna lai chu ‘kawlkil’ a ni a, kawlkil tawpah chuan sunhlu hi a rah phir a. Chu chu pitar-te hian a lo hawlh a, a kung bula tla si hian chhar phak lovah a tla daih zel a. Tin, Pawngeklir pawh hian ek a lum a lum a, kawlkil vengtupa hnen a va thlen chuan, “Hei en la, mihirng reng reng an awm tawh lo, an thi vek tawh a, an zun leh ek pawh ka rawn hlawm a nih hi,” a va ti a.Kawlkil  vengtupa chuan, “Chutia mihring an awm tawh loh chuan lei hi sawi chim vek mai ang hmiang,” a ti a, a sawi ta chiam mai a; chu chu ‘lirnghing’ lo awm \an dan a ni an ti.

Tin, lei hi satel lian pui chunga innghat a ni a, Pawngeklir-in ‘lei chungah mihring an awm tawh lo ve a han tih khan, satel chungah chuan meiling an dah a. A hank al chuan lei chu nasa takin a lo nghing a, lir a lo nghing ta ṭhin a. Chu chu lirnghing chhan an sawi dan chi khat a ni bawk. Chutia lir a lo nghin chuan mihring la dam te khan, ‘E khai, kan la dam e, kan la dam e!’ an ti a, an rawn au chhuak a. Pawngeklir khan dawt a sawi a ni tih an hriat chuan satel chu che lo turin an ti leh ta a ni an ti. Lir a nghin phawt chuan hman laia kan pi leh pute chuan, ‘Kan la dam e, kan la dam e,’ an ti chul ṭhin[1].

India thawnthuah chuan, khawvel hi rul lianpui mai shesha nag an tih chungah a innghat a, a awm hmun a han sawn hian lir a lo nghing ṭhin an ti a. A dang lehah chuan, ramhuai hian tuihnuaiah khawvel (Mother Earth) hi a man bet tlat mai a; Varha Avatar chuan ramhuai chu a that a, a ki hmang chuan khawvel chu a chawi kang ta a. Chutia a ki-a dah rem a tum vel avang chuan lir a lo nghing ṭhin a ni an ti bawk. Lirnghing tuar ṭhang tak Kamchatcha ram bawr, Siberia rama mite chuan ui lian em em mai Kosei an tih chuan, a hmula vur tla a han thin chet avangin lir a nghing ṭhin niin an ring a. Hmanlaia Japanese te chuan maimawm lianpui mai chet avangin a chunga awm khawvel chu a lo nghing ṭhin, tiin lirnghing lo awm chhan an sawi ve bawk.

Heti ang hian keini chauh ni lo, lirnghing tawk ṭhin ramte chuan lir lo nghin chhan hi pi pute thawnthu ah an nei deuh vek mai. Hnam hrang hrangten lirnghin chhan nia an lo sawi ṭhina inang tlang vek chu, khawvel hi engemaw chunga innghat, a phurtu chet avanga lirnghing lo awm hi a ni.

2.         Lei chhungril nihphung: Lirnghing lo awm chhante, a nihphung hre tak tak tur chuan kan lei chhungril chanchin tlangpui kan hriat hmasak a ṭul ang.

Lir lo nghing tawh hrang hranga lei che vel fawn chak leh muan dan mithiamten an zirchianin, khawvel hi kawr (shell) thumin a siam a ni tih an hmu chhuak a, chungte chu- Crust, Mantle leh Core an vuah.

i.        Crust: Lei pawnlang ber, tuifinriat leh kan chenna leilung (lithosphere) hi a ni. Crust chhah zawng hi a inang vek lo nain a chawhrualin km 35 vel a ni a, lei kawr dangte nen khaikhin chuan a vawt a, a ram bakah a zang bawk. Silica (Si) leh aluminium (Al) a tam avangin, sial layer emaw, upper continental crust emaw an ti bawk. Tuifinriat hi km 5 aṭanga 10-a thuk a ni tlangpui a, a innghahna (oceanic crust) hi (km 55 aṭanga 70?)  chawhrualin km 7 vela chhah a ni thung. Hetah hi chuan silica (Si) leh magnesium (Ma) a tam thung, chuvangin sima layer an ti. Sial leh Sima daidangtu hi khawmual hnuai km 11 vela thukah a awm a, Conrad discontinuity an vuah.

ii.     Mantle: Lirnghing lian tham te, tlangkang te, khawmualpui tawlh, etc. awm theihna tura thahrui insiamna hmun a ni. Thil sakhat lutuk lo, tui lutuk lo (semi-solid rock) lum lutuk awmna hmun a ni a, km 2,900 vela chhah a ni. Kan khawvel len zawng zaa 83 zet leh, khawvel rihna zaa 68 zet hi mantle a ni. Km 50 aṭanga 220-a thuka awm, Mantle chunglam, crust hnaihah awm hi thil nem leh nek sawr awlsam tak, tuiril lam a ni a, asthenosphere [Greek: asthenes=chaklo (weak)] an ti. Kan chenna leilung (lithosphere) hi hemi chunga tawlh vel anga ngaih a ni. Crust leh Mantle daidangtu hi Mohorovicic discontinuity an vuah a, km 33 vela thukah a awm.

iii.   Core: Lei chhungril ber a ni a, pressure leh temperature a sang hle (~3x10⁷ atm & ~6000^oC). He laiah hian mantle muk zawng (density) 5.5 x 10³ kgm^-3 aṭangin 10.6 x 10³ kgm^-3 ah a kai sang dawrh a, a chhungrilah phei chuan 13 x 10³ kgm^-3 lai a ni. Khawvel lai tak (centre of the earth) hi km 6371-a thukah a awm. Thil sakhat lam nickel (Ni) leh iron (Fe) a tam a, inner core chu Nife layer an ti. Mantle leh Core daidangtu hi Guttenberg- Weichert discontinuity an vuah a, km 2900 vela thukah a awm.

Pressure leh Temperature te hi a thuk telh telh a, a sang zel a. Mantle-a thil tuiril lam awm chu a sat avangin a lo che a. He lumna hi zunzam nei element-te chatlak lai nei lova a keh ral char char vang a ni a. Hetianga  fawk /fawn vel hi convection current an vuah, a sa zual apiang chung lam panin an fawn a, a chung chuan leilung innek tawnna laiah a rawn irh chhuak ta ṭhin a, tuifinriat chhuat lai tak (mid-oceanic ridges)-ah a chhuak a, hmun ṭhenkhatah tlangkang a lo awm phah bawk. Heti anga fawk kual reng a nih avang hian a chunga awm crust chu khawihin, khawmualpui tawlh a awmtir a. Hei hi plate tectonic movement an ti.

3.         Plate Tectonic Theory: Little, Fowler & Coulson ten kum 1990-a kan awmna leilung (lithosphere) hi zau takin a che vel a ni tia ngaihdan an vawrhchhuah chu Plate Tectonic Theory hi a ni a. Kum 1912-a Alfred Wegener-in, khawmualpui lianpui pakhat (Pangea) a\anga khawmualpui hrang hrang lo awm a ni, tia a ngaihdan Continental Drift a lo vawrh lar tawh leh, kum 1960 chho-a Harry Hammond Hess leh Robert S. Dietz ten tuifinriat mawng keh a\anga leilung hi lo insiam chho hret hret a ni tia ngaidan Sea-floor spreading an lo siam tawhte a\angin Plate Tectonic Theory hi a lo piang a ni[2].

He theory ang chuan, kan leilung hi hlawm (plate) hrang hrangah fel taka in\henin asthenosphere chungah kalhmang neiin, convection current leh tuipui chhuat lai taka leilung irhchhuak avangin a che a. A ch>t chak zawng hi a plate azirin a inang lo. Atlantic tuipui chhuat lai taka plate (Mid- Atlantic Ridge) chet chak zawng chu kut tin \han chak z^wng ang vel kum khatah mm 10-40-a chak a nih laiin, Nazca plate an tih chu, sam \han chak z^wng kum khata mm 160 a ni thung (Zhen Shao, 1997, Hancock, Skinner & Dinely, 2000).

American geophysicist William Jason Morgan chuan kan leilung hi hetiang plate chi hrang 20-ah a ṭhen a, French geophysicist Xavier Le Pichon chuan plate lian zual 6 ah leh a te 6 ah a ṭhen thung. Le Pichon-a ṭhen dan hi mithiam tam berte pawm dan a ni. USGS chuan plate lian zinga mi American Plate chu pahnih- North America & South America Plate tiin a ṭhen sin leh a ni. Plate lian zualte chu- i) Pacific Plate, ii) American Plate, iii) African Plate, iv) Eurasian Plate, v) Indian Plate (or Indo- Australian Plate) & vii) Antarctic Plate.

Plate pahnih an intawhna hmun chu plate boundary an vuah, he lai hmun hi lirnghing thlen tamna hmun, tlang te, tlangkang te, tuifinriat khuarkhurum (trench) leh tuipui mawng tlang dung insiamna hmun a ni. Pacific Plate leh Atlantic Plate intawhna lai bawr zawng zawng hi lirnghing (90% & lirnghing na 80%) leh tlangkang (75%) thlen tam berna hmun a ni a, chuvangin a hming lemah Ring of Fire an vuah hial a ni. Plate intawh dan hi chi thum a awm, chungte chu- dinglam emaw, veilamah emaw insu piala intawk- transform boundary te, a inṭhen hrang zawng- divergent boundary leh a insu zawnga intawk- convergent boundary te a ni.

Mithiamte rin dan chuan, khawmualpui hrang hrangte hi kum vaibelchhe khat kaltaah kha chuan khawmualpui pakhat chauhah a inhlawm khawm a, Rodinia an vuah. Kum maktaduai 600 liam taah khawmualpui 8-ah a keh darh a, kum maktaduai 350 velah inzawmkhawm lehin khawmualpui pakhat a hming Pangea leh tuifinriat pakhat Panthalasa a awm leh a. Kum maktaduai 200 velah Pangea chu khawmualpui pahnih- Laurasia (Asia, Europe & N. America) leh Gondwana (S. America, Africa, Antarctica, Australia & India)-ah a kehdarh leh a. A inkarah tuipui pakhat Tethys Sea  a awm.

Heng khawmualpui pahnihte hi convection current avangin zawi zawiin a phel darh a. Hlawm (Plate) hrang hrangin, hawizawng inang lo leh tawlh chak zawng inang lovin an che hrut hrut a. India Plate pawh hmar lam panin kum khata cm 3-5 a chakin a tawlh ve hret hret a. Plate ṭhenkhat chu a inpersan zawnga an chet avangin khi chat (rift) a insiam a, a ṭhenah an innawr tawm avangin tlang a insiam bawk a. Kum maktaduai 55 velah India Plate pawh chuan Asia Plate nen an insi ta.  An inkara tuipui Tethys Sea a hrut chhoh avangin, tuipui chhuat chu Asia Plate lo sakhat hmukah a nawr chuar chho ta a, Asia Plate lo do letna hi a chak ve bawk nen khawvela tlangdung sang ber- Himalaya tlang dung a lo insiam ta a ni. North- East state ṭhenkhat (Mizoram tiamin) te chu hetia innek tawnna ah hian, a sakhat lo zawk anih avangin, innawr chuar ve tho mah se, Asia Plate hnuai lamah a bir lut thung.

Zirbingna aṭanga hmuh chhuah dan chuan, tunah hian India plate-in kum khata mm 58± 4—a chakin Asia khawmualpui hi kan nek a, Himalayan tlang dung bawrah ringawt hian kum khata mm 17.52± 2 –a nawr chho ang a ni a, hemi awmzia chu kumtin cm 2 zelin Nepal ram hi a nawr tawm zel tihna a ni[3].

Heti anga plate pahnih innawr tawnna aṭang hian thahrui tam tak a inchhek khawl zel a. Leilung (earth crust) in a dawl loh chin a chaklo laiah khi chat (fault) a siam a. Innek tawn reng na na chu pelh sawlh thut emaw, pial thut hun a lo awm a, thahrui a rawn chhuah a, lei a lo nghawr che ta dur dur a, lirnghing kan ti. Lei khi chat (fracture) insiam chawp leh awm sa tawh inpelhsawlhta (fault) aṭangin lirnghing a lo awm a ni tih hi, kum 1906 daihtawh khan Prof. H.F. Reid-a chuan a lehkhabu Elastic Rebound Theory ah chiangtakin alo hrilhfiah tawh a ni. Leilung f^n theihna in a tlin tawh loh tawp (elastic limit)- ah hian, kum tamtak chhung thahrui lo inchhek khawl tawh (strain accumulation) kha vawi leh khat ah a rawn chhuah ta thut ṭhin a, hei hian lirnghing a rawn siam ta ṭhin a ni.

4.         Lirnghing lo awm chhan dang: Kan leilung insiamrem leh chet vel (tectonic movement) avanga lirnghing tih loh, heng ahnuaia tarlante avanga lir lo nghing te hi chu a pawnlang a, a nep deuh bawk. Lirnghing lo awm chhan dangte chu:-

1)    Tlangkang

2)    Leimin lian tham- lei emaw vur emaw tawlh nasa

3)    Tuikhuah lian (dam) a\angin: e.g. Koyna Dam (India), Zipingpu Dam (China)

4)    Tuikhawhthla nasa

5)    Lung hal te, bomb lian tham- Nuclear/ Atom bomb puak te, etc.

6)    Oil siakchhuahna, Lungalhthei khur aṭangin: e.g. Sichuan (China) earthquake

        Tuikhuah lian (dam) te, lungalhthei, etc. khur aṭanga lirnghingte hi leilung inpelhsawlh (fault) hmuna siam  leh din, khuarel leilung zia tihdanglam vanga thleng a ni. Heti ang (dams, oil, coal mine, etc.) awmna hmun zawng zawngah lirnghing a thleng kher lo.

II.         LIRNGHING ZIA LEH NIHNA ṬHENKHAT:

Lirnghing hi khawi hmunah pawh, engtik hunlai pawha thleng thei reng a ni. Lei chhunga a lo nghing \an theihna hmun hi lei khi chat a ni deuh vek a, hmun dang a\ang pawha insiam thei tho chu a ni. Lei chh<ng km 700 aṭanga pawnlang deuh km 30 v>lah a insiam ber a. A nghing \anna hmun hi focus emaw hypocenter emaw an ti. Focus a\ang hian kil tinah a nghawr kual nghal vek a, a chung zawn chiaha lei pawnlangin lirnghing a tuar hmasaber a, helai hmun hi epicenter an vuah. Lirnghing nghawr nat zawng inang kual chh<ng hi isoseismal an ti. Epicenter hnaih apiangin lirnghing nghawng an tuar nasa a, lei th^wl leh chhah si hmunah a nghawr a muang deuh na a, hmun dang aiin a nghawng a na thung. Lei pawnlang a\anga lirnghing insiam \anna focus thuk lam hi focal depth tia sawi a ni.

Focus a\anga lo nghawr (f^wn) chhuak hi seismic wave an vuah. A nghawr kal chak zawngte leh nghawr dan azirin chi 4-ah \hen a ni, chungte chu- i) Primary wave (P-wave), ii) Secondary wave (S- wave), Love wave (L- wave) leh Rayleigh wave (R- wave) te. P-wave hi second khat chh<ngin km 5-8 a kal thei a, a chak ber a, lei chh<ng khawi hmun pawh a kaltlang thei a, a kalkawng thil- in, etc. awm a vawrh k^ng thei a, a nghawng a na vak lo. S- wave hi a kawkalh (a sir zawngin a vawrh) z^wnga f^wnin second khatah km 3 v>la chakin a kal thei a, P- wave ai chuan a nghawng a na z^wk, thil tuirilah a fawn tlang thei ve lo thung. P- wave leh S- wave te hi lei chh<ngrilah nghawr kualin lei p^wn l^ng lamah a rawn nghawr a, body wave an vuah, GSI (Geological Suvey of India) mi hmasa R.D. Oldham-a hmuhchhuah a ni a, hemi a\ang hian lei chh<ngril awmdan hmuchhuaktu a ni bawk. Lir a lo nghina P-wave leh S- wave inthlauhna second zat hi 8-in puntir ila, chu chu kilometer-a teha lirnghing lo thlenna- epicenter hlat zawng ang v>l a ni.

British Mathematician A.E.H. Love-a hming chawia phuah Love wave (L-wave) hi lei p^wnlanga nghawr a ni a; chhim leh hmar zawnga f^wn a nih chuan chhak leh thlang zawngin a nghawr \hin. Lord Rayleigh (John William Strutt)-a hming chawia phuah R- wave (Rayleigh wave) hi seismic wave ho zinga thawk na ber a ni a, a f^wn vir av^ngin thil khawih chhetu ber a ni. Heng seismic wave te hi lirnghing nghawr tuartu mihring t^n hriat hran hman a ni lo va, lirnghing tehna kh^wl (seismogram) a\angin a thliar hran theih chauh a ni. H>ng seismic wave-te hi a kalna kawng a zirin a f^wn chak z^wng a inang lo zung a, an kal theihna hmun pawh a inang vek lo. Hei v^ng hian achunga tarlan tak- lei chhungril nihphung pawh kan hriat theih phah a ni.

Lirnghing nghawr nat z^wng hi a insiamna khi chat (fault) sei zawng, a zau zawng leh a thuk z^wngah a innghat a. Lei khi chat km 25-a sei hian magnitude 6.5-a na vel a siam thei a, sq.km 100 v>la zau in magnitude 6.25 v>la na a thlen thei bawk[4]. Chuvangin focal depth thuk ah chuan lirnghing lian tham a thleng \hin. Mizorama lirnghing kan tawh tam berte hi lei p^wnl^nga insiam a nih av^ng leh, a focus a hlat \hin av^ngin kan tuar n>p a ni.

A tehna lam: Lirnghingin in leh lo, ram a khawih chhiat d^n azirin Intensity teh a ni a. Hmanraw hmang lovin lirnghing nghawng d^n a\anga sawi \hin a ni. Epicenter a hlatin lirnghing nghawng hi a na lo \hin a, leilung pianhmang inang lo leh insak d^n phung pawh inanglo leh mihring bit zawng pawh inang lo tak tak a nih \hin av^ngin Intensity hmanga lirnghing nat zawng sawi chu a rintl^k t^wk lo hl>. A tehna chi hnih a awm, chungte chu- Rossi Forrel’s Scale leh Mercalli Scale/ Index a ni. Mercalli Scale hi a lar z^wk a, t<nlai milin an siam danglam a, Modified Mercalli Scale (MM Scale) an ti tawh, mihring thil siam in leh lo chhiat nasat d^n azirin tehkhawng chi 12 a awm. Roman number I a\anga XII thleng a awm, a nambar s^ng apiang hi intensity s^ng a ni mai, e.g. III: Feeble, IV: Moderate, V: Relatively Strong, VI: Strong, etc. Khawthlang ram tam tak chuan European Macroseismic Scale (EMS- 98) an hmang a, India ramah chuan Medvedev-Sponheuer-Karnik (MSK) Scale hman uar a ni thung.

MSK Scale hi Sergei Medvedev (USSR), Wilhelm Sponheuer (East Germany) leh Vít Kárník (Czechoslovakia) ten kum 1964-a an rawt chhuah a\anga hman \an a ni a, hei v^ng hian MSK-64 tiin an sawi bawk. He scale hi India, Israel, Russia leh British awp ram \henkhatten an hmang a. USA-in intensity teh n^na a hman m>k MM Scale nen pawh a inz<l hle. Lirnghingin a nghawng huamchh<nga thil awmd^n thl$ra teh \hin a ni. A teh kh^wng hi chi 12 tho awmin, decimal nambar pumpelh n^n Roman number I a\anga XII hman a ni. Ch<ngte chu:-

I.        Not perceptible (A nghawng hmuh leh hriat theih loh): Lirnghing tehna seismographs-ah a hriat theih chauh a, thil tihchhiat a nei lo.

II.     Hardly perceptible (A nghawng hmuh leh hriat harsa): Lung muanga awm, mi \henkhat ten a nghing tih an hriat theih. Thil tihchhiat a nei lo.

III.   Weak (Hriat theih chang chang): Mi \henkhatin lir a nghing tih an hre thei a, thil khai eng ilo chu a sawi th>n a, in chhia erawh a awm lo.

IV.  Largely observed (Mi tam berte hriat tham): Inchh<nga awmten an hre deuh vek a, p^wnah chuan mi tl>m z^wkte chauhin lirnghing an hre thung. Nghing nasa lutuk lo, zawi lutuk lo anih tawh avangin mi \henkhat chu an chiai a. In leh inchhung bungruate hmuh theihin a nghawr che ve hret a, hluma siam b>l te, darthlalang te, tukverh leh kawngkhar a nghawr ri a. In chhia erawh a awm lem lo.

V.          Fairly Strong (Na thawkhat): Inchh<nga awm tam z^wkten an hre thei a, pawn lamah erawh hriat a harsa. Mi \henkhat chu an chiai avangin hmun him awm ngaihtuahin an tl^n v>l ruai tawh a. In leh inchh<ng bungrua a nghawr nghing lawih lawih tih a hmuh theih a, thil khai phei chu a then nasa hle. Hlum leh darthlalangte a inkhak ri ruk ruk a. Kawngka leh tukverhte a invaw bawk. Tuizem khat deuha tui dah phei chu a fawk liam hial a. Inchh<nga ranvulhte thunun an har a. In sak \halo leh himlo chu a chhe nual bawk.

VI.        Strong (Na viau): Inchh<ng leh p^wna awm tam zawkten an hre thei a. Mi \henkhatte chu ding nghet thei lovin an tlu bawk. Mi tam berte an mangan av^ngin an chiai a, inchh<nga awmte an tl^n chhuak a. Inchh<ng bungraw \henkhatte a awm sawn a, thil te tham phei chu a tla a. Hlum leh darthlang lam a\anga thilsiamte a keh a. In \henkhat a chhia a, cement in-plaster a khi a. Leiah khi tam tak a siam bawk.

VII.     Very strong (Na tak): Mi tam berte chu an chiai a, p^wna tlan chhuah an tum a. Inchh<ng bungrua leh bungraw dang, almirah, etc. te a then sawn b^kah a tlu a. Chhuara thil dah ngheh lo a tla vek a. Tuizema tui dahte a per sung sung a. In sakna rei tawh- upa deuhte, in sak \halo leh himlo \henkhat a tluk sawp b^kah a chhe nasa hle a, leimin a siam nual bawk.

VIII.   Damaging: Inchh<ng leh p^wna awm tan din hleih theih a ni lo. Bungrua a tlu a. Lei pan deuhna laiah a nghing a hmuh theih a. In sakna rei tawh a tlu sawp deuh vek a. Lei khi kak nasa tak a siam a,  lung tla leh leimin a tam hle.

IX.        Destructive: Mi zawng zawng an chiai a. Lei nghawrin mi a paih dawrh dawrh a. Lei nghawr a hmuh theih a. Mumal taka duan insak pawh a nghawr nat avangin a chhe nual a, a dang phei chu a tlu sawp deuh vek tawh. Lei hnuaia pipe phum a chhe vek a, lei a khi nasa a, leimin nasa leh lian tak a siam bawk.

X.           Devastating: In pangngai him a awm tawh lo va, insak \ha leh lian pawh a chhe nasa. Dil leh lui te a kuang a fawn liam a, tui a lian a. Leimin rapthlak tak tak a thleng bawk.

XI.        Catastrophic: In leh mihring siam thil chhe lo a awm mang lo. Lir nghing a nasat em av^ngin dam khawchhuah ngaihna a awm mang tawh lo va, tsunami a thleng bawk.

XII.      Very catastrophic: Lei leh lei chh<nga mihring siam thil a chhe vek a. Leilung pianhmang a danglam dawrh a, lui kuang a sawn bawk. Tsunami a thleng.

Seismograph-a seismic waves f^wn zau z^wng (amplitude) hmangin lir a lo nghinga thahrui p>k chhuah a\angin lirnghing teh \hin a ni a, hei hi magnitude an ti. Kh^wl hmanga lirnghing tehna seismograph ang hi kum 1855-ah Italian scientist L. Palmieri-an a siam chhuak a. T<nlai hun thlenga hman seismograph siam chhuaktu chu John Milne a ni a, kum 1880-ah Japan lalin a sawmna anga Japan rama hna a thawh laia a tih chhuah a ni.

Kum 1935 khan California Institute of Technology-a thawk Prof. Charles Richter leh Beno Guttenberg te chuan lirnghing magnitude tehna (scale) a duang chhuak a. He magnitude scale-ah hian 0 a\anga 9 thleng awmin a nambar tam apiang hi lir nghing nasa entirna a ni. Hei hi Ritcher Scale emaw Local magnitude (M_L) emaw an tih chu a ni. He tehnaa nambar-te hi a inthlau hle a, magnitude 7.5-a na lirnghingin thahrui a pek chhuah hi magnitude 6.5-a na lirnghingin thahrui a p>k chhuah l>t 30 zet hu a ni a; magnitude 6.5 pekchhuah thahrui hi magnitude 5.5 thahrui pekchhuah l>t 900 v>l zet a ni thung. Hiroshima-a atom bomb puakin thahrui (energy) a pekchhuh leh magnitude 6.33-a na lirnghingin thahrui a p>k chhuah a intluk vel a ni.  Kum 2010 January ni 12 tlai lamah Haiti ram chu magnitude 7.0-a na in a nuai a, February ni 27 tlai lamah Chile ram chu magnitude 8.8-in a nuai bawk. Chile rama lirnghing hi Haiti ramin a tawrh lirnghing l>t 501 v>la na a ni. Kum 1960, May ni 22-a Chile rama magnitude 9.5-a na lirnghing kha chhinchhiah china khawv>la lirnghing na ber a ni a, mi 4,000 chuang an thi a. Kum 1556-a China ram Shensi ram biala lirnghing (M 8.0 v>l)-ah mi 8,30,000 v>l zet an thi a, hei hi lirnghing av^nga mihring thi tamna ber a ni. Heng mite hi lung chang lutuklo, p<k chhunga ch>ng leh khawsa an ni a, lirnghingin a nghawr chim av^nga thi an ni ber. Lirnghing pakhatah magnitude a danglam thei lo va, intensity erawh epicenter a\anga a hlat d^n leh thil dang av^ngin a danglam thung.

Ritcher Scale/ M_L hi epicenter a\anga km 100 bawr v>lah a rintlak hle a, mah se lirnghing lian tham M_L 6.8 chunglam leh, epicenter hlat zawng km 600 chin chunglamah a rintlak loh thung. Hei v^ng hian kum 1979 kh^n Thomas C. Hanks leh Hiroo Kanamori te chuan moment magnitude (M_w) scale (MMS) an tih chu an siam chhuak a. Lirnghing lo chhuahna hmun leilung dinhmun te, a siamtu lei khi chat (fault) sei zawng leh zau z^wngah te a innghat a, Ritcher scale hi seismograph-a lirnghing nghawr nghin dan a\anga siam a ni thung.  Lirnghing v^ntlang magnitude 5.0 ah te chuan a danglamna a awm hran lo va, a chunglamah a inang lo nual a ni. MMS hi lirnghing tenau magnitude 3.5 chin hnuailam teh n^n a \ha vaklo thung a, h>ngah chuan Ritcher scale te hi an hmang lar a, lirnghing lian thamah chuan MMS (M_w) vek hi hman a ni tawh.

Khawv>l pumah kum khatah lir hi vawi nuai nga (5,00,000) v>l nghing ziah anga chhut a ni a, vawi nuai khat zet chu hriat thama nghing a ni a, a dang 100 chuan chhiatna a thlen anga chh<t a ni. USGS ten an chhut dan chuan, magnitude 8 chin chunglam hi kumtin vawi 1 a nghing a, 7.0 – 7.9 hi vawi 18, 6.0 – 6.9 hi vawi 120, 5.0 – 5.9 hi vawi 800 leh 3.0 – 5.0 hi vawi 55,000 (nitin vawi 150 aia tam) thleng \hin ang a ni a. Lirnghing lian tham apiang hi a nghing hun chh<ng a rei a, a nghawng pawh a na a, lirnghing hriat tham leh lian kan tuar tam lo hi a vanneihthlak viau a ni. 

Lirnghing lian tham lo thlen hma hian hmun \henkhatah chuan na vak lova nghing a awm \hin a, hei hi foreshock an ti a, km 10 tal-ah main shock a awm \hin. A hnu lamah vawi khat emaw a aia tam emaw nghing nawn a awm leh \hin bawk, chung chu aftershock an ti thung. Foreshock hi hriat lawk harsa tak a ni a, a hnu lawka na zawka lir a lo nghin kh^n lirnghin hriat hmasak zawk (ni thum chh<ng emaw, ni thum hma ngeiah) kha foreshock vuah a ni mai a, a hn<a mi a nat zawk loh chuan main shock tiin an sawi leh \hin.  Lirnghin av^nga lei che v>l insiam rem leh hian aftershock hi a siam a ni.

Khawv>la lirnghing na leh lian z^a 81 leh lirnghing z^a 90 v>l zet hi km 40,000 v>l zet sei, sakawr ke-bun ang (horseshoe-shaped) pian nei, sq. km 103 zeta zau Pacific Plate bawr v>lah a thleng \hin a, heti lai hmun hi circum- Pacific seismic belt a ni a, Pacific Ring of Fire tiin an sawi \hin. Hei hian ram hrang 10- Chile, Mexico, United States, Canada, Russia, Japan, Philippines, Indonesia, New Zealand leh Antarctica te a huam a ni. Mi thiamte chuan lirnghing hi planet dang- Hrangchhuana (Mars) ah te, Chawngmawii (Venus) ah te, Jupiter h>ltu thl^ ah te, Saturn h>ltu thl^ leh kan lei h>ltu thl^ (moon)-ah te khian a thleng ve \hinin an sawi bawk[5].

Lirnghing tehna kh^wl seismograph hi hmun tam takah bun a ni a. Lir a lo nghin hian, a nghing \anna hnaih ber seismograph kh^n a hre hmasa ber a, seismic waves hi a kal kual av^ngin khawv>l letliam daiha mi pawhin a lo record tho bawk a. H>ng khawl dahna hmun hrang hrangte hi internet kaltlanga inzawm an nih deuh vek av^ngin, a hre hma ber pathum emaw, a aia tam emaw a\ang khan lirnghing an hriat hun an chh<t a, lirnghin \anna hmun- epicenter leh a nat zawng- magnitude an puang \hin. Internet-ah hian lirnghing thar lam tar chhuahna website a awm nual a, ch<ng zinga pakhat chu hei hi a ni- http://www.imd.gov.in/section/seismo/dynamic/welcome.htm

Lirnghing zirmite (Seismologist) chuan lirnghing lo insiam d^n tl^ngpui chu hre tawh mah se, hmun hrang hranga a lo pian chhuah d^n kimchang leh mumal tak hi an la hriat kim theih tlat loh av^ngin- lirnghing lo awm hun t<r te, engtia na in nge tih leh a nghingna hmun t<rte hi tun thleng hian an la sawi lawk thei lo.  

III.       INDIA HMARCHHAK LEH MIZORAM DINHMUN

|hen khatnaa tarlan tawh angin, India plate leh Eurasian plates te hi hmas^ng ata lo innawr tawn tawh a ni a. Kum 100 a lo tlin hian, Asia plate hi hmar z^wngin cm 200 zet kan nawr z>l ang a ni a. Heti ang inn>k tawn a\anga thahrui lo inchh>k kh^wl hi lirnghing hmangin a lo inpaih th^wl tawh \hin a. Ch<ng zinga India hmarchhakin kan tawrh zinga a na zualte chu- Shillong lirnghing (M 8.2, June ni 12, 1897)- mi tam z^wkte pawn lama an awm lai tlai dar 5:15 v>la nghing mi 1,542 thihna, sq. mile 30,000 bawra in zawng zawng chhe vek khawpa lirnghing nasa, India rama lirnghing chhinchhiah hmasak ber te, Kangra (H.P) lirnghing (M 8.0, April ni 4, 1905) te, Shrimangal (Assam) lirnghing (M 7.6, July ni 8, 1918) te, Dhubri (Assam) lirnghing (M 7.1, July ni 2, 1930) te, Nepal-Bihar lirnghing (M 8.3, Jan. ni 15, 1934), Assam lirnghing (M 7.2, Oct. ni 23, 1943) te, Arunachal Pradesh-China inrina b^wra lirnghing (M 8.5, Aug. ni 15, 1950) mi 1,520 thihna leh, la hnai ber mi 400 v>l an thihna Manipur-Myanmar inrina b^wra lirnghing (M 6.6, Aug. ni 6, 1988) te a ni.

India hmarchhak hi khawv>la lirnghing thlen tamna ram/ khawpui paruk zinga pakhat a ni a. Ram dangte chu Mexico, Taiwan, California, Japan leh Turkey te a ni. Kum 1965-a\anga Edward A. Flinn leh Eric R. Engdahl ten khawv>la lirnghing thlen duhna hmun (F-E regions) 729-an ziah chhuah chu Seismic Region 50-ah an \hen a (as per revised in 1995). India hmarchhak hi Region 26-na India- Xizang- Sichuan- Yunnan seismic region-ah min dah bawk.  T<nhma lama lirnghing lo tuar fo tawh leh tuar m>k, tuar thei reng kan nih av^ngte, kan leilung dinhmun leh pian\o av^ngte hian, India rama mithiam rual kalkh^wm Bureau of India Standards (BIS) chuan India hmarchhak zawng zawng chu Mizoram tiamin - lirnghing na ber thlen theihna hmun Seismic Zone V-ah min dah ta a ni.

Epicenter awmna hmun azirte, lei inpelhsawlhna hmun azirte leh leilung pianhmang azirte in India hmarchhak hi lirnghing thlen theihna hmun nga-ah \hen a ni[6].  Chungte chu- 1) India Plate leh Eurasian Plate-te khawchhak lama an insutna lai, 0-40 km-a lirnghing insiamna, 1941 (M 7.1) leh 1947 (M 7.8) thlenna- Eastern Himalayan Collision Zone te, 2) Bay of Bengal a\anga Mizoram khawthlang lam, Nagaland ram huamin India khawmual Asia plate-a a bir l<t zawnga a chetna bial, km 200 v>la thuka lirnghing insiam tl^ngpui leh a lian tham (M ≥ 7.0) vawi 10 lai thlen tawhna Indo- Myanmar Subduction Zone te, 3) India Plate leh Burma Plate- intawhna, Po Chu fault-a insiam Great Assam Earthquake (1950, M 8.7) thlenna Syntaxis Zone te, 4) Shillong te, Mishmi tlangdung leh Assam phai bawr- Shillong Plateau, Mishmi Hills and Assam Valley Zone te, leh 5) Bengal phaiz^wl lirnghing tuar na lutuk lo leh a vantl^ng (M ≥ 5.0) tuar \hin Tripura- Mizoram tl^ng ram- Bengal Basin and Tripura- Mizoram Fold Belt te a ni. Hemi huam chh<ngah hian fault lian tham panga a awm- Meghalaya tlangchung z^wl leh Bengal phai su tlangtu Dauki fault te, hmarchhak zawnga inkham Sylhet fault (Mat fault-in a zawm) te, chhim leh hmar zawnga inkhawh Jamuna fault te, hmar thlang zawnga inkham Tista fault te, Mizoram chh<nga hmar-thlang leh chhim-chhak zawnga khi chat Mat leh Tuipui fault te hi a ni. Heng huamchh<ng ringawtah hian, kum 1762 a\anga chh<tin lirnghing vawi 787 a thleng tawh a, h>ng zinga vawi 531 chu M 5 hnuai lam niin, vawi 113 chu M 5 – 6 inkar a ni. M 6 – 7 inkar hi vawi 41 a thleng a, M 7 – 8 inkar hi vawi 6 a thleng bawk[7].

Satellite thlalak a\anga Mizoram chh<nga chiang taka lei inpelhsawlh/ khi chat (fault) kan hmuh theih chu mat fault hi a ni. Ding lam z^wnga pelh sawlh (right lateral strike slip) a ni a, hei hian MMS/M_w 7-1/4 thlenga na lirnghing siam thei t<ra ngaih a ni[8]. He lai hmun hi englai pawha che reng t<ra ngaih a ni a, kum 2005 a\ang khan kumtin hunbi neiin GPS hmangin a ch>t chak dan endik \hin a ni a, kum 2 chh<nga a ch>t chak d^n chh<tin kum khata mm 38 – 48 v>la chakin a che a, hei hi hemi chungch^nga zirbing tlangkawmna a la ni lo thung[9]. India plate ch>t chak d^n kum khata mm 10 – 15 a\anga chh<t chuan a chak viau a ni. Lirnghing tenau (M 3.0-4.3) engemaw zat chu kum reilote chh<ngin hriat a ni bawk. Mat lui hnaih khuaah hian seismograph a awm loh av^ngin lirnghing zin leh nat d^n kimchang erawh hriat theih a ni lo thung. Mat fault b^ka fault dang kan neihte chu- Aizawl fault, Tuipui fault, Thenzawl fault, Saitual leh Sateek fault te a ni.

Chhinchhiah theih china Mizoramin lirnghing kan tawrh nat ber chu February ni 4, 2011 zan dar 7:25-a nghing kha a ni a, M_w 6.4-a na a ni.  Hei hi Mizoram pumin kan hria a, thi leh hliam an awm hriat a ni lo thung. Epicenter tak hi Burma (Myanmar) ram lam niin 24^o 616’ N & 94^o 740’ E a ni a, km 88.8-a thuk a\anga in\an a ni. A nghawng nat d^n hi MMS hmanga (ka) chh<t chuan III-IV v>l ang a ni.    

Mizoram, Nagaland, Tripura, Arakan Yoma tlangdung leh Andaman & Nicobar Islands thleng hian Indo-Burma Arc (IBA) emaw, Indo- Burma Region (IBR) emaw tih a ni a. Km 3500 bawr vela sei niin Eurasian Plate (Asian Plate) hnuaia India plate bir luhna- subduction zone anga ngaih a ni. Hemi bawr hian lirnghing pawh a thleng zing viau a ni. Lir lo nghing tawh d^nte thlirin, lei p^wnlang lam (km 20-40) a insiam chi lirnghing- shallow focus a ni deuh ber a, magnitude 3.0- 5.0 a tam ber bawk.

Kan ram a naupang?  Hmun \henkhat- lung l^kna hmun (quarry), kawng kam leh lung poh chhuak a\angin hmanlai nungcha ruhr>l leh ramhmul (plants) lunga chang ta (fossil) leh an ch>tna hnuhma (trace fossil) a\anga zirin, Mizoram hi tuifinriat p^wnl^ng (shallow marine) lam deuhah a lo awm tawh \hin a. H>ng fossil-te hi heti ang hmuna ch>ng chi an nih v^ng a ni. Geology-a ngaihd^n lar tak chu- t<n huna thil thleng leh hmuh theihte hi hmanlai hun hriatna hnar a ni (Present is the key to the past: by Charles Lyell) tih hi. Fossil hmuh chhuah tawh \henkhatte hi t<nlai pawha tuifinriat kam b^wra ch>ng, hmuh theih rengte an ni hlawm. Fossil \henkhatte chu khawv>l ram dang, hmun hrang hranga awm, hun thuhmuna ch>ng, t<n hn<a a tak hmuh tur awm tawh si lo a awm bawk a, index fossils an ti. H>ng hmang hian a awmna ram pian hun/ upat z^wng an chh<t \hin a, oil zawn n^n a \angkai hle bawk.

            H>ng fossil hmuh chhuah a\angte hian kan ram hi, kan \henawm Myanmar (Burma) aia naupang a ni, a tih theih a. India hmarchhak ramte hi leilung tlakh^wm (sediments deposit) a\anga ram insiama lo awm kan nih av^ngin tl^ngk^ng kan t^wk ngai lo va. Lei chh<ng thil hlu- lunghlu leh lung mawi dang beisei t<r a awmlo bawk. Leilung inn>kna b^wra awm, innawr tawn av^nga chhim leh hmar zawnga tlang dung lo awm phah sung mai leh leilung naupang, lei th^wl leh lung chang \ha pawh neilo kan nih av^ng hian lirnghing hi a hlauhawm hl>. Heti ang leilungah hian lir nghing f^wn v>l a muang a, a nghawng a na thung. A z^ng thei ang bera insak a him a, d^n famkim z^wma hmanraw \ha leh mithiam kan chhawr thei d^wn anih chauh loh chuan concrete in lian sak a him lo. Ram tam taka lir nghing an tawrh tawh d^nte zir chianin, inchh^wng 2/3 aia tam sak a himlo lehzual.

REFERENCE:                                  

Amateur Seismic Centre (ASC) 2008. Earthquake in Mizoram and Tripura [http://www.asc-india.org/]

Ayothiraman R., and Hazarika H., 2007 (Eds). Earthquake Hazards and Mitigation, I.K. International

Bureau of India Standards (BIS). IS: 4326 – 1993 “Earthquake Resistant Design and Construction of Buildings Code of Practice”

Deptt of Earthquake Engineering, IIT Roorkee, 2006. Earthquake Risk Management, National Disaster Management Division, Ministry of Home Affairs, GoI

Dowrick, David J., 2003. Earthquake Risk Reduction, Wiley (England)

Hemmady, A.K.R., 1996. Earthquakes, National Book Trust (India)

National Information Center of Earthquake Engineering (NICEE), IIT Kanpur [http://www.nicee.org]

http://www.wikipedia.org (Earthquake, Plate Tectonic, Seismic wave, etc.)

http://saarc-sdmc.nic.in/index.asp

National Earthquake Information Center (NEIC) [http://www.neic.cr.usgs.gov]

Nandy, D.R., 2001. Geodynamics of Northeastern India and the Adjoining Region, ABC Publications (Calcutta)

Laldinpuia, 2010. Lirnghing lakah kan him angem? in VANGLAINI Daily Newspaper on 1.4.2010.

Mahapatra, G.B., 1994. Text Book of Physical Geology, CBS (India)

Martin, Stacey and Walter Szeliga, 2010. A Catalog of Felt Intensity Data for 570 Earthquakes in India from 1636 to 2009 in Bulletin of the Seismological Society of America, 100, No. 2, 562-569, April 2010.

Sharma, M.L. and Shipra Malik, 2006. Probabilistic Seismic Hazard Analysis and Estimation of Spectral Strong Ground Motion on Bed Rock in North East India, 4^th Intl Conf on Earthquake Engineering, Taipei, Taiwan, Oct 12-13, 2006

Tiwari, R.P., 2000. Status of Seismicity in the North-East India and Earthquake Disaster Mitigation

United States of Geological Survey [http://www.earthquake.usgs.gov]

Power Point Presentations of- Prof. V.K. Gaur (IIA, Bangalore), Prof. J.R. Kayal (CSIR Emeritus Scientist, Jadavpur Univ., Kol.), S. K. Biswas (ONGC), Harsh Gupta (NGRI), Saurabh Baruah (NEIST, Jorhat) & Prof. R.P. Tiwari (MZU).

[Article for Mizoram Science Journal, 2012: ‘Best Article Award 2012’]

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1 B. Lalthangliana, Pi Pu Chhuahtlang, 243.

[2] http://www.wikipedia/plate tectonic.htm

[3] Billham, et.al, 1997 by using GPS measurement

[4] Dr. Lalliana Mualchin, Final Report for Earthquake Hazard Map of Mizoram Project (Unpublished)

[5] Margaret Glasscoe, NASA/ JPL scientist

[6] Nandy, D.R. (2001). Geodynamics of Northeastern India and the Adjoining Region. ABC Publications, Calcutta, 209

[7] M.L. Sharma et.al, Probabilistic Seismic Hazard Analysis and Estimation of Spectral Strong Ground Motion on Bed Rock in North East India, 4^th Intl Conf on Earthquake Engineering, Taipei, Taiwan, Oct 12-13, 2006

[8] Dr. Lalliana Mualchin, Final Report for Earthquake Hazard Map of Mizoram Project (Unpublished)

[9] Prof. R. P. Tiwari, Supervisor, GPS Measurement of Crustal Deformation across Mat fault- A transverse fault across the Indo- Burmese Arc in Mizoram (DST Project ongoing; in presentation)