Size Distribution of Bottom Sediment in the South China Sea
by
Siriporn Pradit aad
Charumas Meksampan
Asian Fisheries Developmetrt Center Ttaining Department
Southeast
TD/RE5/69 A u e u s t : 0 0 . 1
Size Distribution of Bottom Sediment in the South China Sea
by
Sidportr Pradit and
Charumas Meksampan
Southeast Asiar Fi8heries Developmetrt Center TiairiDg Department
TDRES/69 August 2002
Bibliographic Citationl Siripom Pradit and Cha$mas Mekampan
Size Distribution of Botton Sedinent in the South Chim S€a
TD/RES/69 TrainingDepertnent, SouthealtAsian Fisheries
Development Center, SmutpEkan. l3pp.
Size Distribution of Bottom Sediment in the Soulh China Sea
SiriporD Praditr aod CbaruEas MeksampaD':
SEAFDEC/TD, PO.Bor 97, Phrftr'nut.hedi.Sdrnurpmkan 10290,Thriland.
rFruhy olFnheries. KasersdUiiversity. Chatuch*, Bdkok 10900, Thail.nd.
ABSTRACT
Thc $udy olsizc disribution of boton scdincnr {as conductcd in rhrcc ircas o f t h e s o u r h c h i n . s e a d n r i n g 1 9 9 5 r o l 9 9 9 c o n s h r i n g o f r h e G u l f o f T h n i l a n d a n d E a e Cor{df Peninsular Mahysia.West Coistof Sabah. Sarawakand Brtr.ei Ddrussxlrfr atrd Vietnamese ware6. Sardand s/ris rhe nrin on rhe boltom of lhe South Ciina Sea wnh.ccounring for 26.26% rnd 24.57% ftspectivel!. Srndy silr, silL! snnd, clny, snnd a.d sfrc/and sa"d drro,eaccounh lor22A6%,t651qi686%.229% and0 57%,rcspecrirely Sand $as !ich in rhe Southem p!n ofTh!il0nd, Peninsultrr Malaysin rnd the Sourhert prd of Vietnam. Silr was rbundut in rhe Culf of Thniland, of shore of Srbrh rnd Nodhern p.n orVidrnan. Srnd:r Ji/r *rs dispersed in ihe CullofThaihnd rnd neI thd shoft ot Srbrh Srrawlr. Stly r"nd coveN lhe botrom in Southeln part ol Tnailand and oli'sho€ ofSabrh S!nw.k.C/ry is spEad in of{hoft ofSabah. A mixrure of srrd rrd rhel/appea6 in rhe Peninsul.r Mrlaysir rid sourhern trd ofviernrm. srrd rnd eore h d i f i u s c d i . r h e C e n l r u L p a l t o f V i e l n ! m .
Key eolds: botronr sedinent. size di$riburion, sourh China Se{.
Table of Contents
l l rl
r)
1)
7)
The Srudy Area
Maredals and Methods Res!lt
Discussion
Ackno$ledgemenl
Reference Inlroduclion
Appendir
L
List of Figures
Fig.1. Depth contour 0fthe Soutb ChinaSea
Fig .2. The Gravity CorEr
Fig.3. The s€dinetrl sampling using gravity corEr
Fig. 4. Snith-Mdnrye Grah
Fig.5. The sanpling statjoo the South Chitrr Sea
Fig.6. Sift drslflbur.on 0f bonon sedimenr in lhe Soub ChinaSea
sedimeot com (a) clay. (b)sand
s€dinent cole: (a) silt, (b) silly sand sedinent colt of sandy sill
lrl
Page
2
4 4
t0 Fis. ?. The honogen€ous
Fig. E. The honogetreous
Fig. 9. ]le homogeneous
List of Appendix
PJge
Appcndir l. Sampling dale, appanrus used. deplh 0fobtained coft' 14 a r d w a t e r d e p l h i n th e C u l f o f T h a j l a n d r n d E a s l C o a (
A | 1 p e l l i r I L S r m p l i n , , l . r e . J p p r . r u . u , c J . d c p r h u ' u b r r i n e J c o R . . t5
and walerdepth in the Sabrh. Sxfllvlk lnd Brunei Drrussalan
Appcndii IILSNnpling dare, appurtus used. dcpth ofobrdined coRs. 16
J r r l s d t e r t l e p r h i n V i c r n J m e \ c $ a t e A
Aonn tcdiml in the Sonh Chith S&
Introduction
Scdrmenrs rE knopn to be rhe key ro uncie!. Md hr$oiical envionm.nrs. A s c q u c n c c o l s c d i m c n t a r t l a t e ^ c t r n r c l l t r s rh o u r e r v i n r m c n r c h . n g c r o r c r r i m c
( H r l l b e r y , 1 9 9 2 ) . T b c s i z e o i s e d i n r e n L e $ d . r s r i b $ r h e r y p . o l s e d i n e n r a n d r h e l o u N e ol borh. Anrlysis of rhe panicle sizc dnd shrpc nry phvide imponoi clu.s ro rhc
sedinentpmvenance.tansporr.biioit$ddcp.sirio.co.dnionsrlso(KcDncrhl994).
In thirildt th. nain obj.crive ,a\ ir b inv.srigde the size di*ibnrbn ol rhc botrom scdim€m in rbe SourhChina Sca.Thc scdincnr type in rhc upperlay.r {tunnll srntling iarions givcs I bNd vics ofrhc scdimenr dhkibdrion. Th. ftsuhs fDo this (udy sill be uteful fundarnenrrl'.td. in rcnnsofrhe ellrioDship bcrwccn si7f, of s.dimcnr lnd rhe livine marin. animlin.!sc thrl scdineor is rhe sub$rarc olnlrin.
h e n r h i c f r u t r n r n d r h c s t r b $ r l l e c o n d i r i o n s r r c r n i n p o n a n r f a c r o r i n r h e n d i { r i h u l i o n Threc rreas were selected und* thcjoint ressch prcjcd thar aar c0tried oul by Sotrrhc!iAsirnFhheries DevclopmcnrCcnrc!/ltaininE Dcpftnen(SEAFDEC/
'lD) dnd rhc SEAFDEC Marine Fishcry RcsoDers Developftenr and Mlnrgchcnr Dcpunocnr (MFRDMD/ Maliysia)in 3c(ing !p { collaborative ReselEh pmjccr in thc GulfoiThoilond ond ENr Cofr ofPc.insuhr Mllaysialnd wes cor$ oi s.b.h, Sm*rk ond Arunci Drmssahn b.tsccr 2l April to 23 May 1996 Md 25 April ro ul Mdy 1997. Esp.crittly Collaborarion bctvcen TD .nd Mernrm.se Fishe.y !n\rirurc eas scl !p lo clrry out collaboraavc Ese!rch ir Victnrmese warers betNcen 25ADril ro 25runc l999.Allthe rurlcyr wea caricd using M.VSEAFDEC.
ludinB fbn th. literaruE Ericws ! fcw judies conceminC rhesiz.di(ribution in rhc Sourh Chinr Se! havc bccn conducrcd. Itr rhc Culf of Thail!nd, ulmorr rl1 reserrchc$ in rhe folmer rimes hrd conc.nr.t.d onlt in rhe aca closc ro rhc !ivc6 d i s c h r r g i n g i n h r h e u p p e r G r l l o f T h n i l n n d
2. Thc Srudy Arc!
The Sourh Chinn Sea isone of$.l.rarn conrinenral seni-clGed 5.!swirh!n rE! oul1,600,000 tmr. rhe bcrndeprh is Ll30 rh. ThcCftalcst depth is in rh..cnkal blsin rtubout5.m0m (D.V Uu and J-M Br.nl.d, t997). ThEe aEas in lhc Sou(h China Sea wee iudicd, Firnlt iheGulf of Thaihtrd rnd Peninsular Mrliysir nnnins fon lonsirudr 99'E to 104'E ald fom 2 N ro 12" N pheE rh. rv.og. deprh is 5,1 m.
S.condly, rhc s!rc^ of Wesr Co.$ oI Strb0h, Srrawrk rnd Brun.i Datusulrm sraniig fton lonsirude 109'Eb ll7. E Md s!'N ro 7,'N. whee rhe nelr shore depth is 0 n to 70 m a n d o l l : s | s E d e p r h e x c c e d s 1 0 0 0 n lh i d l y V i c t r r n e s e s a r e r s r a n i n g l r u m 1 0 3 , E t o l l 2 ' E 0 t r d f r c m 2 1 , N t o 7 , N , in ih c N o h c r n p r i c h a r a c r e r i z c d b y s h n l l o w , w i d c
south.ttt A:id Frh.net D?t.loryent Centrl
conrinenral sh.lfwith a water deprh fonl0nto30n Th€ cental Pon ch arac te rized by a narrcw contirenial shelt Its width is being 40 kn io 50 kn ftet $at rhe water d;Drh €iches l0o0 m io 2OOOn. Thc soulbern pan ischlracterized bv awidccontincntal sh;lf sheF the rar.rdepdis ron zom lo 60n The d.plh conlous has b.en illusrrrt'd
!t- L D.prh contoutorthe sourh China sea t 1 6
Aanon sedin nt in the Sdth China Saa
3. Matcrails snd Mcthods
Coilecdd of Sedinqt Srwl.s
Th. sanples w.e collectcd usins ! sruvny coEr (sc Fis. 2 lnd Fis. 3) rhar consisrins of 0 corc barEl ol hallow mctl. Thc corc b.ftl contains rcmovlblc plasic linc6*hich fir inroacoE brrEl and drin rhc sedimcntsanolc. thcDlanic lin.rwas 85 cm lon8and 5.2 cm in insidcdirmeier DrrinS scdim.ntcollecrion,rhcgraviiycorr w r s l o w e r c d r o th e d . f t h o f . b o ! r 2 a b o v c t h c s c a b o t o m i n s h r l l o r r a t e r ( l e $ r h s i 3 0 0 n ) r h e n s r o p p e J I t u 2 m i n s u b s e q l e n l y i r s u r 0 l l d w e d t o s i i k f i e e l y l o l h e b o n o n Additioully a Smith -Mclntyre srab thrl rB!coveEdbsins 0.05 m: Gce Fis.4) wls uscd in ! few sdions inst.ldoirh.coErwhcEth. bononw conpos.d nainly of sand lnd grav€l rhar could .ot be Ericr. by thc corcr A big sravity coEr sas osc inne{d or th. small sfuvil, coErin Srbon. Sarluat and Brun.i D0o$al!m w.rcrs in thc lnrt *ven sahplins station. The leD8lh of rhc phstic liner wos l2O cn a.d lh.
Eighry one sdmpling rbtions wcrt cholen in thc Otrlf oi Thliland ond tad Codst ofPelinsular M010ysio. Sirty.iour $!mpling starions w.N chos.n inWe$ Cori oI Sabah, Sarasak rnd Brunei Drrussalan ond rhiiy- four samplina saiioft ,eE sampled tn Metnrmcs. wale6.Th. sanplirg iltionsnft shosn i, b.en illun ar.d i.
F i s . 5 .
The lengrh of $cdinentcdft wos n.osuNd rhen rhe appc!!0nces ol thesedincnr wcrc Ecorded by vi3!.1 obsdvatjon, A fin. groin size ofock rcpEscnted beins.r.d, fin. gtait size and loft scdinenr EpEscnrcd iilt and a rine sticky ar.in size w.s classcd ascl.y.Anount olclay moE rhan sili cpns.nredsilr, cl.y. rnountof saDd moE rhln sih EpG.m.d.ilry.ull anounr oasih noc lhan saod Epcsenredlnd, dll !a.d mired shcll n classd d red rld.!.11. .nd sand *irh sto.. Epescmcd ttld ttd 3ro!..Atod lmn rhis, rhe homoacneous s.dim.nr coc ( rhe san. siz. of sedimenl thnush th. scdim.m co€) sill bc rcodcd.
A surface lay.r (2 cm of lhe upper lay.O of lll sedimen( coEs rnd rh.
honogcneous s.din.DtcoE w.Eus.droDlotan i6rg.of lhc siz.dhtribution inth.
Srrttr4! )!n,) t'\tr!"\ tt\,:lrrrr.t L.ttl
Fig I T c,l
Bdon ydinent in tr. SauLl Chtna Sea
Fii. 4. Smid-M(lnrrc Cr$.
!
o o
A
i !i!.-. *-. 'rliiir r i a
\ !-!'!!!!. r r
\_i,'!!i:. '
sussE!: !!..
-i"Y.i- 1., -
FU.5. The qnrlitrEdanon r rh. souLh Chinr Sea.
Sruth.ai ljinn Fkh.ti.: D.\tl, pttur Ctthr
4. R$ult
All rhe surfrce layer (2 cn of the upp€i layer) one hundred rnJ sevcnry nine sflnplirg srtions weE dore(seeAppendix I,II dd III), rllofthe strrf.ce laycr (2cm of upper lsye! ). The sizedisribudon ofthesedimeni oi rhe survet aEas weft mrinly end and J/raccounring fat 26.29% zad 24-51%, Especlively of the sa'npling rEa.
Sand! silt, silry sDd. cla!, stud tud src/l and s.nd rrd s,ore accounrtot 22.46%.16.51tk, 646%. 2.29% nlltJ.51%,respecrively Gee Fig.6)
Srrdwas rich in rhe Southern part of Thailand, Peninsular Malaysia and the s o u r h e r n p a n o f v i e t n a m . S i / t w a s p l e n d f u l i n t h e G u l f o l T h a i l a n d , o t r s h o E o f s a b a h and Noihein pan olMernnnese wates. $rdysilrwas dispersed in the GulfofThriland rnd near shoft ol S.bah, Sffawak ond BMei D.rusalam. Si/t/ sand is found in the Sourhen pan oI $e Guli oi Thailand rnd ol1:rhoE of sdbrh, Srrawrk and BruDei Daruss.lam. C/ayis spread in off'shorc ofSabah.Alirdes,nd.rdsr.l/was ditruscd 1n rhe Peninsular Mrlrysia.nd rhc sourhern part of vieham. A liule srrd ds.ore
Tbc !o6og.!our 3.din .t cor.
Eisbty one homoeenous sedinre weE d*oiibed d sii( si/./s@4 en4 sd-r sr'lr and clry. Th.se accoumtbr39.5l%, 16.05%,14.81%,14.81q'and 14,81% Espdctivdlr.
( F i g . 7 a b , F i g . 3 r b a n d F i g . 9 )
C/ry \'!s found i. ofr lhoe ofsabah rnd vietnanes wrte6. slJ. spEads in rheGullolThrilrnd,otT-shorc Sabah and Northern pan ofMelnlnese wnreir. Silr/
rrdcoveed off shoft Srtawak and the war.6 ol Nonhern pan oMetnan, S,d
*as distribuled in the Southern prrt of Vietmn. the coastal of Sibah,Saiawak and Brunei D.russalam, and ncar sho€ ofPeninsularMallyril Sa'dl l'r was disDe6ed betwcen .he southern pan olvietnam and near shoEot Sabah,sarawak md Brunei
Brnln vJin?nt in th. Sruth Chlnu Sto
t 0 2 1 0 4 1 6 1 0 8 1 1 0 1 1 2 1 1 4 1 1 6 1 1 8
Soukeai As@n Fishcn.s D?t?Lrrt.tt C?nter
(b)
Fig,7, Th! h.m.geneous !edim.n' coE (a)drr (ht qnd
Banan sedtn rt in the Soah Chiha sea
P i & 3 . T h . h o m e s r n . o u s 5 e d ' m e r r . o E : G ) n l t , i b r e l r y q n d
SoulheEt Atid Fish'ia Dee.lapmat Cenkr
li& 9. Th. noncgcncous scdin.
10
Sut n \Ji'utt in tlE Srtth Chn). S?a
5 . D i s c u s s i o n
Ctu:r wlr dinnbured tom rhe \hrLli,u salef deprh rrcutrd 100 m to rhc doep w a r e l s s i t h i d c p r h r o u n d 2 , 0 0 0 m . T h e p a r i c l e s j z e o f c l d y is r h c s n d l l e n o l r l l redrmefb (lnr sedincnt size reler to the Udden-wctrrwoih Arrin size scrlel and so Day be tdnsponed ior long diirnc.
Si/r is dndbuted from ihe shallow Mrc6 in rhc CullolThaildnJ ro rhe deep wrrcrs whcre lhc Jeplh i! abour 1.600D(otr-rhordlSnraw warert. Silty sub*rares v r s a n i m p o i a n r h a b i t a t f o r r d l v e s c r n d v i l o r o u s b i o l o l i c r l c o m m u n i ( y . k ' n a y b e
i m p l i c d r h a t i n t h e C u l f . f T h a i l r D d , N o n h c r d p i n d l V i e r n r m e s e w r r e A r n d n e a r r h e s h o E o f S ! . r w r k M r e r s rr c r h c l r x r s o u t o c o f li v i n g r n i m a l l n d a c r h e E f o E e o o d
nshiDe grlutrd for demcrsal firh.
S,'dwas disriburcd ftum rhc shnllo{ wrrs6 10 rhe deep warers wirh deprhs oi ahour 1000 m .The weathcring ol srndn.nc pnvide an import source of sand, n o r m a l l y . s a n d b c s c c n in t h e o p e n o c c a n S r n d w a s w i d e s p r r d i n r h e S o u r h e r n p m r o t t l r e G u l t o f T l r a i l d n d a n d P e n i n s u l r r M c l a y s i a t h r t b e r a D s p o r l o D r rh c b c . c h a r d ncfr-horc arcrs Srnd and silry snrd sub$fdcs was suitablc hrbifut lor sohc kind ol l r l u r u E s k ' d i e s . r h e r e l x r n r n s h i p o l { y p e o l s e d L m c r r l r d m r i n c b c n r h i . l r u i n s h . u l d b e in v e s i g r l e d .
6. Acktrowl€dg€m.Dt 'lhe
aurhorwoold likcro rh.nks ro Dr Sonboon Snirxksophon for his uscful c o m n r e r s o n r h c n u t r u r c r i p ( . S i n c e r t r p p f t c i x r i n i s e x l r e r s e d r o a l l c r e w o i M.VSEAFDEC for ensuring sucessn'l field ooemrions I am ako eEdful b Mr WR B. Elnow lorcollecring rhe English in $i tapcr
D . V U u x n d J M B r a n k a n . l 9 9 T . S e a s o n a l V m a r i o t r o f T e m p c r a r u r e r n d S i l j . i r y F j e l d and wrlerM$ses in thoBlen DonE (Sotrrh Chinr) Sea M,.hl. Conpot Mpdenlnt.
V o l 2 6 . N o . 1 2 , p p . 9 7 1 1 3 .
Hrllbery.R O 1902 Sedimens Thenl erncrion
"nh Sio8eocheDical Cycles lhFu8h Fonnarion rnd Dilgeneris. Itr Oloh,Arq&n r.rri!r/C].Jcs: Acrdc'ni. Prsr. pp Kcnnerh. e 1994. Sedimenrhn\port and Depositional Ptocesscs: Prupcrtics ofsediDrenr
prnicles. Cambridge UniveNity PEss. Englrnd. pp. l-2,1.
l 1
S.rth.ti Atiun Fithenet De\thptta, C4nr
App.ndir I. sampliDs date. ryp Ds u$d. dcDrh ofobrlincd cd
rh.culrorThrilard indEaiCer$of Pciii{l Mrlrysia.
Artkn r.Jnn.nr i, tle Souh Chna *t
App.dL tr, Samplins dd.. rpprrlrs in rhc s'brh_ sarrwat aid
:f;fi i
