ATOLL RESEARCH BULLETIN

No. 86 ^HARLES H. LAMOOREW

February 28, 1965 BOTANY DEPT.

UNlVERSllY OF H A W A I I HONOLULU 14. H A W A I I

ATOLL RESEARCH BULLETIN

Geography and land ecology

of

CZ;Pperton Idand

by

~ a r i e - H 6 l ; n e Sachet

Issued by

THE PACIFIC SCIENCE BOARD

National Academy of Sciences-National Research Council Washington, D.C., U.S.A.

ATOU RESEARCH lNlUXTN

---..---

NO.

86

Geography and land ecology of Clipperton Island by

Marie -&'lbne Sachet

Issued by

PACITE EClENCE BOARD

National Academcy of Sciences-4?a'tlonal Research Council Washington, D. C.

February 28, 1962

It i s a pleasure to conmend the far-sighted policy of t h e Of'fice of Naval Research, with i t s emphasis on basic research, as a r e s u l t of which a grant has made possible the continuation of t h e Coral A t o l l Program of t h e P a c i f i c Science Board.

It i s of i n t e r e s t t o note, h i s t o r i c a l l y , t h a t much of the f'unda- m n t a l Infomaation on a t o l l s of the Pacific was gathered by the U. S.

Navy's South P a c i f i c Exploring Ekpedition, over one hundred years ago, under the cormnand of Captain Charles kfillres. The continuing nature of such s c i e n t i f i c i n t e r e s t by the Navy i s shotm by t h e support f o r the Pacific Science Board ' s research programs during the p a s t fourteen years.

m e preparation and issuance of the A t o l l Research B u l l e t i n i s a s s i s t e d by f b d s from Contract N70nr-2300(12).

The sole r e s p o n s i b i l i t y f o r a l l statements made by authors of papers in the A t o l l Research Bulletin r e s t s with them, and they do not necessarily represent the views of the Pacific Science Board o r of t h e e d i t o r s of the Bulletin.

E d i t o r i a l S t a f f F. R, Fosberg, e d i t o r

M. -H. Sachet, a s s i s t a n t e d i t o r

Correspondence concerning the A t o l l Research B u l l e t i n should be addressed t o the above

P a c i f i c Vegetation -Project

$ Natioml Research Council

2101 Constitution Avenue, N. W.

Washington 25, ^D. C., U.S.A.

CONTENTS

. . .

INTRODUCTION 03

Geographic location. general description

. . .

³

. . .

i s t o r i c a l sketch 4

W E A T H E R A N D C m T E ^{. . e . e e e . . e e e e e e} e . 9

. . .

Temperatme 9

. . .

Atm~pheric press- 1 0

. . .

Winds 810

. . .

Tropical storms and hurricanes 12

. . .

Rainfall 20

. . .

Aixmspheric humidity 24

. . .

Cloudiness and v i s i b i l i t y 024

HYDROGRAPRY

. . .

²⁵

Surfacecurrents

. . .

²⁵

. . .

²⁶

. . .

Tides 27

. . .

ocean temperatures 28

SUBMARINETOPOGRAPHY . e * * * . e e e e e . e . . e 2 9

. . .

Ocean floor. Clipperton Ridge 29

. . .

Ocean bottom 29

. . .

Undersea mountain 30

. . .

Upper slopes and t e r r a c e s 31

. . .

I n t e r p r e t a t i o n 32

Reef

. . .

^{. . 3 2}

. . .

SURFACE F E A W S OF LAND STRIP

35

. . .

Owter shore

-35

Beaches

. . .

³⁵

Beach Rock

. . .

³⁶

m d

. . .

³⁸

Beach ridges

. . .

³⁸

. . .

Land surface 39 Unconsolidated material

. . .

³⁹

The ledges

. . .

³⁹

Exposed pavements

. . .

⁴⁰

Lagoon shores

. . .

⁴¹

Lagoon c l i f f s

. . .

⁴¹

Other lagoon shore types

. . .

⁴¹

ClippertonRock

. . .

⁴²

.Analysis of Clipperton lagoon water

. . .

⁴⁶

Lagoon l e v e l

. . .

⁴⁷

. . .

Lagoon.depth and nature of bottom 48 Lagoon r e e f s and i s l e t s 49 LITHOLOGY...

. . .

m 0 . 5 1 Loose sediments

. . .

⁵¹

Boulder and cobble gravel

. . .

⁵²

Fine gravels. sands. silts. and mixtures of these

. . .

^{5 3} Beach conglomerates

. . .

⁵⁸

Phosphatic conglomerates

. . . ~ . ~ ~ . ~ . .

^-58

Pumice and other extraneous materials

. . .

^.65

Analyses of Clipperton Island samples _{. .}

. . . .

⁶⁶

iii

PHYSIOGFUPHIC CHANGES.

. . .

⁶⁹

Geological change

. . .

⁶³

Historic jl. change due to natural causes

. . .

⁶⁹

Recent changes due to man

. . .

⁷²

GENERALLAUDIEOLOGY

. . .

⁷⁵

ET8bikL-t

. . . *

⁷⁵

~azld iota

. . . ⁷⁶

p u t l i f e

. . . ⁷⁶

Vegetation of t h e lagoon

. . . ⁷⁹

Animal life

. . .

⁷⁹

Marrrm&ls

. . . ⁷⁹

BWLS

. . .

⁸⁰

Reptiles

. . . ⁸⁴

Invertebra-tes

. . .

⁸⁴

. . .

Ecological history 86 CATALOGUE OF LAND AND LAGOON PLANTS AND ANIMALS

. .

⁸⁹

Plants

. . .

⁸⁹

. . .

A n W s

94

BIBLIOGRELW

. . .

¹⁰³

PREFACE

During t h e I i l t e r n a t i o n a l Geophysical Year, Scripps I n s t i t u t i o n of' Oceanogaphy, a branch of t h e University of California, organized s e v e r a l research c r u i s e s i n t h e P a c i f i c , a s p a r t of t h e world-wide propaiii,

Several previous c r u i s e s had c a l l e d a t t e n t i o n t o Clipperton Island, and during t h e Doldrums Expedition of t h e surntner of' 1958 it was decided t o study t h e biogeography of t h i s l i t t l e - l m o ~ m is l a n d . A Zroup of 1 3 per- sons were l e f t on t h e i s l a n d by t h e Research Vessel Spencer F. Baird on August 7, 1958 and were taken aboard a a a i n on August 26, excFpt f o r four who remained u n t i l September 25 t o c o n t i m e t h e i r s t u d i e s of sharks. I had t h e g r e a t zood f o r b e t o be one of t h e group and t o study p l a n t l i f e on t h e i s l a n d . I n a d d i t i o n I made observations on t h e l a n d fauna and seology, and some c o l l e c t i o n s of animals, s o i l s and rocks.

It w i l l not be easy t o thank adequately t h e uany persons who have contributed t o t h e success of my work on C ~ i p p e r t o n . I n t h e f i r s t p l a c e of course I 17a11t t o express my g r a t i t u d e f o r t h i s unique opportunity t o Scripps I n s t i t u t i o n of Oceanog-aphy and t o i t s Director, D r . Roger Revelle.

I owe xuch a l s o t o D r . Carl Hubbs, f r o i whom t h e i n v i t a t i o n rms received, t o I@. John A. Knauss, l e a d e r of tlle D o l d r ~ l i ~ ~ s 3:yedition, t o t h e l a t e Conrad Limbau~h, chief of t h e Clipperton f i e l d party, t o a l l my companions i n t h e f i e l d and t o t h e Master and crew of t h e Baird. Our v i s i t could n o t have taken place v i t h o u t t h e a u t h o r i z a t i o n of t h e French Goverrxent, and without t h e i n t e r v e n t i o n of D r . Jean Delacour, then Director of t h e Los Angeles County N ~ ~ s e ~ l m and Professor Roger Heim, Director of t h e Ivluse/unl National d H i s t o i r e Naturelle i n P a r i s , rho helped procure t h i s author- i z a t i o n . The French Embassy and t h e Office of the Naval ~ t t a c h g i n Vasn- ington vere a l s o very h e l p f u l ,

For p e n i l i t t i n s me t o join t h e expedition and. encouraging ~ile t o work up t h e m a t e r i a l , I wish t o thank my s u p e r i o r s i n t h e U. S. Geological Survey and i n t h e P a c i f i c Science Board, fiJationa1 Academy of Sciences-- National Research Council. The Acadeioy a l s o provided very welcoule help i n t h e fom of a g r a n t froii! tlle Joseph Hznry Fund. I cannot nac!e here a l l t h e persons who have contributed i d e n t i f i c a t i o n s , analyses, and suz- z e s t i o n s and .to whom I am deeply g r a t e f u l . They w i l l be mentioned i n t h e course of t h e paper. In assembling b i b l i o e r a p h i c m a t e r i a l and photographs I have benefited from t h e f a c i l i t i e s of many i n d i v i d u a l s and s e v e r a l o r - ganizations: t h e U. S. Navy's Naval History Division, Hydrographic Office and Office of Naval Research, t h e Service Historique de l a Nariile Na- t i o n a l e of France, t h e U. S. Weather Bureau, t h e U. S. National IG~seur,, t h e U. S. National Archives, t h e Library 02 Congress, t h e C a l i f o r n i a Acaderkv of Sciences, and t h e ~ i b l i o t h & u e Nationale of France.

Miss Evelyn L. P r u i t t , Head. of t h e Geography B r a ~ c h , Office of Naval Research, gave me much help i3 searching f o r photographs and d.oc~ments

i n t h e U. S. Navy f i l e s . Nessrs. E. C. Allison, Ted. Arnow, Willard Bs- corn, A. I. Coopeman, A. S, Hambly, L e s t e r F. Hubert, W. L. Klatre, Job1 Knauss, H. S. Lad.d, Conrad Limbaugh, W. E. Nalone, H. 2. Naude, C. S.

Rali~age, Waldo S c h d t t and R. E. Snodgrass gave me unpublished information, l e n t me photographs and documents, o r read and c r i t i c i z e d p a r t s o r a l l of t h e urnnuscript. M r . V. A. Rossi gave me advice and help ~ i i t h t h e il- l u ~ t r a t i o n s , alld. D r . Gilbert, Corwin examined t h e samples of v o l c a r i c rocks.

I wish to make s p e c i d mention of M r . Obermiiller, ~ e ' o l o ~ u e en Chef de l a France dfOutre-Mer, who worked on Clipperton a few m n t h s before I went there and gave me copies of h i s reports even before t h e i r publi- cation, as w e l l as samples of h i s rock collections.

F i n a l l y I wish to express my appreciation and g r a t i t u d e to Dr. F. R.

Fosberg who helped and encouraged me i n every s t e p of t h i s work.

The appearance of t h i s paper has been delayed by various circumstances, as has t h a t of a more extensive and profusely i l l u s t r a t e d memoir on Clip- perton (sachet, i n press).

Geographic location, general description

Clipperton Island ( ~ i g . l ) , one of t h e few oceanic islands i n t h e Faatern Pacific, e x c i t e s the i n t e r e s t and c u r i o s i t y of n a t u r a l i s t s

especia3ly because it is the only c o r a l i s l a n d in t h a t p a r t of the ocean The nearest a t o l l , Arkapuka i n the Eastern Tumotus, l i e s 2300 n a u t i c a l miles t o the southwest.

Here are some other f i g u r e s that w i l l give an idea of the i s o l a t i o n of Clipperton, t h e coordinates of which are 10ol8'N and 10g013'W (adjusted position f o r Astro 1957, a monument placed by t h e U. S. Hydrographic

Office on the northeast side: 1 0 ~ 1 8 ~ 41"N, 109Ol2' 3 4 " ~ ) . The nearest land i s the Mexican west coast, 600 n a u t i c a l miles t o the north-north-east.

The nearest i s l a n d s ta the north are the ReviUagigedo Islands of which Soccoro is 530 miles from Clipperton. The Galapagos l i e 1300 miles t o the southeast and Easter Island 2250 miles due south.

In i t s general form, Clipperton i s a low closed r i n g of c o r a l lime- stone, but the i s l a n d does not exactly qualify as an a t o l l a s a small volcanic rock r i s e s a t the end of a short peninsula i n the lagoon. This t y p of island has been c a l l e d an " a l ~ ~ ~ s t - a t o l l , " b u t t h i s category i s not very n a t u r a l and formstions have been placed in it which may have n o w i n conanon beyond the fact that they include both c o r a l and volcan- i c features. For t h e purposes of t h i s description it seems p r a c t i c a l to consider the i s l a n d as an a t o l l , the only one in the eastern t h i r d of the Pacific Ocean. In area, Clipperton Rock i s very

m,

^cornpazed t o t h e c o r a l ring, and observations so f a r seem to Fndicate t h a t it has l i t t l e influence on t h e ecology of t h e FsZaad. No m~lcroscopic p l a n t s grow on the Rock, except f o r some lichens.

The c o r a l r i n g i s somewhat egg-shaped and synnnetrical along a northwest-southeast axis. This a x i s falls a l i t t l e north of t h e Rock, which i s c l o s e t o the southeast coast of t h e island. The r i n g is con- tinuous and encloses a brackish lagoon. Only a small minority of a t o l l s are closed and few of these have a r i m as narrow a s Clipperton 's, around such a compazatively large lagoon. The g r e a k s t dimension of the atoll, along t h e NW-SE axis is 4 km and the circumference of the a t o l l r i n g about 12 km. The emerged Land s t r i p is widest along the northwest c w t , w i t h a maximum width of about 400 m i n the west corner. The average width i s under 200 m, and in narrow places it is much less. In August 1958 t h e northern part of the northeast coast measured only 45 m from lagoon ta ocean. That a r e a of t h e land was a l s o the lowest, r i s i n g only

0.65 m above estimated mean high t i d e level. Generally the ground slopes up f m t h e ocean to t h e tops of t h e beaches o r boulder ridges, and gently down again toward t h e lagoon so that t h e highest point of any given ocean- lagoon s e c t i o n i s the c r e s t of the outer beach o r boulder ridge. This c r e s t v a r i e s i n a l t i t u d e , reaching a maximm of about 4 p. The volcanic Clippertan Rock l i s t e d on c h a r t s a s 29 m high, i s v i s i b l e from every

of t h e atoll. From a small boat i n the lagoon t h e land rim i s v i s i b l e all m d , b u t appears very low. In fact one has the impreseion of floating

i n an immense saucer f u l l of water and with a very low rim. Oceaaward, the land rim i s surrounded by a r e e f - f l a t l y i n g a t about low t i d e l e v e l . On t h e ocean side, t h e o u t l i n e o f t h e atoll i s p r a c t i c a l l y f e a t u r e l e s s and smooth. The lagoon shores m e more i r r e g u l a r , with s e v e r a l small peninsulas aad bays. Half way along the northeast side the small tri- angular Green Point ( ~ o i n t e Verte) j u t s i n t o the lagoon (see map). On the southeast side, Clipperton Rock

cl ocher

c l i p p e r t o n ) r i s e s a t the end of a small peninsula, t h e Isthmus ( Isthme); Thumb Point ( ~ o i n t e du Pouce ) extends northward from the Isthmus, separated from the Rock by Thumb Cove ( ~ n s e du Pouce). Between t h e Isthmus and the landstrip, the lagoon forms an arm c a l l e d Rock Bay ( ~ a i e du p ocher). J u s t west of the Rock, another peninsula, The Hook (Le Crochet), s t r e t c h e s northwestward i n t o the lagoon.

The abandoned quonset v i l l a g e and the l a r g e coconut grove on the southwest 8-ide of the a t o l l a r e located along a small bay, Pincer Bay ( h i e de l a Pince) formed by two peninsulas, North and South Pincers ( ~ i n c e Nord and Pince ~ u d ) . Other recognizable f e a t u r e s a r e t h e 5 ^Egg

Islands ( 1 l e s ~ g g ) along the northwest side, and the U. S. Hydrographic monument ( ~ s t r o 1957) and small group of coconut palms marking N a t u r a l i s t s 1 Camp ( C W des Naturalistes) n e m the East corner of the island.

H i s t o r i c a l sketch*

Clipperton I s l a n d i s named a f t e r an English buccaneer, John Clip- perton, who i s reported t o have seen it i n 1705. Clipperton, who was t r a v e l l i n g with the famous p r i v a t e e r and n a t u r a l i s t William Dampier, deserted and s t o l e a Spanish p r i z e bark i n which he crossed the Pacific, a remarkable f e a t . There is no account of t h i s voyage during which the i s l a n d is supposed t o have received i t s name (Barney 1816), and i n t h e description o f Clipperton

'

^s second voyage (Beta& 1728)

of the e a r l i e r discovery, b u t the name was indicated on o r 1735 (Moll).

Various authors (Toni010 1919, Mexico L i g l q ) have Spanish navigators may have seen the i s l a n d e a r l i e r , i n centuries, o r even t h a t Magellan m y have discovered it 1934). The i s l a n d would then be i d e n t i c a l with ~ e & o s

no mention i s made maps about 1730

suggested t h a t t h e 16th o r 17th

i n 1 5 U ( ~ u n n and San Pablo (Magellan). Historically, such considerations a r e of g r e a t i n t e r e s t but as far a s our s c i e n t i f i c knowledge of the i s l a n d is concerned they a r e immaterial, as it i s q u i t e unlikely t h a t ancient descriptions w i l l come t o l i g h t .

Our knowledge of the island, and the extensive l i t e r a t u r e concerning it, then begin i n 1711. On April 3, Good Friday, two small French vessels, the Princesse and the Mcouverte, who had lef% Brest together i n 1708?

met with an unknown i s l a n d which was named I l e de l a Passion. The Captain of t h e S c o u v e r t e , Michel du k c a g e , and a passenger i n the Princesse, Mr.

de Frudhomme described the new island, the one i n h i s l o g and the other

*

^{For a} more d e t a i l e d treatment see Sachet 1960.

in h i s diary. Their discovery was first raentioned i n p r i n t in 1725 (Ia W b i n a i s Le ~ e n t i l ) , while t h e i r accounts were published in extenso i n a French report (France 1912). The o r i g i n a l documents are

kept

^{i n}

the French N a t i o n d Archives.

M r . du Bocage described Clipperton a s "A l a r g e Rock, cragged and jagged, a t the south point of a very f l a t island.. ^{. I 1} The northeast side,

"sandy with s o w brush and a dried-up t r e e on the north-east point, was but a very narrow tongue of land. The center of t h e i s l a n d was a large lake reaching from one side t o the other. The west side appeared t o have some low brush with s o i l and some rock b u t very low, although a l i t t l e higher than t h e e a s t side." M r . de Prudhomme a l s o described the very low sandy island, without any t r a c e of inhabitants, unwooded e x c e ~ t

f o r some very low bushes, and with some dead t r e e s on the sea shore "as i f they had been thrown up by the currents."

!These b r i e f accounts a r e remarkable i n t h a t they describe Clipperton much a s it appears today f'rom aboard ship, except f o r the recently added coconut t r e e s and various t r a c e s of human a c t i v i t y .

There can be no doubt t h a t I l e de l a Passion i s the i s l a n d now c a l l e d Clipperton. The coordinates given i n 1 7 l l were:

Du Bocage 10028 'N, 263050 (ll3g3W ~ r e e n w i c h ) D e Prudhomme 10018-19 'N, 268011' (10G 2 7 ' ~ )

(From the latest o b s e m t i o n s , t h e coordinates a r e 10~18 'N, 1C)3*13

'

W)

.

Over a hundred years l a t e r (1832), an American sea-captain, Morrell, described the is.l.md a s he saw it i n August 1825: "It i s low a l l around near the water, b u t a high rock r i s e s in the centre, which mzy be seen a t the distance of six leagues..

."

A s f a r as lmo-vn, Morrell and h i s men were the f i r s t t o land on Clipperton.

Except f o r a small sketch map, poorly oriented, which M r . de Prudhomme mentions and which i s kept with h i s diary and r q r o d u c e d i n the French r e - p o r t (1919), Clipperton Island was f i r s t mapped by S i r Edward Belcher and the map published by the B r i t i s h Admiralty i n 1849. I n May 1839, when Belcher v i s i t e d it, the island was ( ~ e l c h e r 1843): "a very dangerous low lagoon island, d e s t i t u t e of t r e e s , with a high rock on i t s southern edge, which may be mistaken f o r a s a i l

. .

^, L%e b e l t of l a n g l i t e r a l l y consti- t u t e s two islands, formed by i t s two openings

. . .

^" (see fig.4, facing p. 69).

A f e v years l a t e r , ^a, French ship owner, M r . Lockhart, arranged t o take possession of t h e unclaimed i s l a n d f o r France and t o e x p l o i t i t s phosphate deposits. Thus it came about t h a t i n 1858, one of Mr. Lock- h a r t 's m r c h a n t vessels, 1

-

'Amiral, Captain Detaille, Master, a r r i v e d a t Clipperton. Lt. Victor Le Coat de Kerveguen, who had received a s p e c i a l commission f o r the purpose, took possession of the is-land f o r t h e Second 'Empire on November 17, 1858. The h i r a l

--

then proceeded to Honolulu whera the necessary papers were f i l e d t o amounce t o the world t h a t the i s l a n d was now a French possession. Le Coat de Kerveguen took notes on what was observed on Clipperton and h i s manuscripts, sketches and maps are w o d u c e d

i n the French r e p o r t (1912). I n 1858 the c o r a l rim was closed, the lagoon s a l t y , t h e r e was no vegetation, but g r e a t numbers of sea birds.

Some s o i l samples were collected, b u t exploitation of the phosphate deposits did not seem worth while and was not then undertaken.

I n August 1861 (Pease 1868) a young American, L t . Griswold, who l a t e r l o s t h i s l i f e a t Antietam, v i s i t e d Clipperton Island and found it uninhabited, covered with b i r d s but devoid of vegetation. The lagoon w a s closed, i t s water f r e s h and f u l l of a water p l a n t which he collected.

This f i r s t botanical specimen from Clipperton was sent t o the California Academy of Sciences i n San Francisco and l o s t i n the 1906 f i r e .

J u s t who discovered phosphate deposits on Clipperton Island i s obscure.

They were known to b c l i i a r t i n 1857, and Griswola was on a phosphate e x p l o r a t i o n t r i p . I n 1892 Frederic W. Permien made several t r i p s t o Clipperton to survey the deposits and i n 1893 the Oceanic Phosphate Company of San Francisco s e n t two men, Jensen and H a l l , t o survey t h e i s l a n d and begin exploitation (Anon. 1893). The observations of Jensen, and h i s e x c e l l e n t sketch-nap are reproduced by Agassiz (1894, pp. 174-175). Jensen had collected a piece of t h e volcanic rock, which was i d e n t i f i e d a s a trachyte.

A t the same time, A. Churchill Fisher made observations on tides (u. S.

National Archives). W. C. M a t t , of t h e Schooner Anna

-

^{of San} Francisco, surveyed the phosphatic deposits probably i n 1897, and h i s map is available i n the Archives. Also i n 1897, P. J. Hennig ( ~ n o n 1897) prepared a map, which he forwarded t o the U. S. Hydrographic Office. It was promptly published a s an H. 0. Charrt (no. 1680), replacing the c h a r t s based on Bel-

cher's sketch, and remaining i n use by a l l navigators u n t i l t h e French survey of 1935.

Exploitation of the Clipperton phosphate proved d i f f i c u l t and not very profitable, and several companies were t o attempt it one a f t e r the other before the i s l a n d was abandoned during World IIas I. When the French war ship Duguay-Trouin arrived a t Clipperton i n Nov. 1897, a small c a p w a s discovered w i t h t h e e employees of the Oceanic Phosphate Co., who hoist- ed t h e U. S. flag. France protested, the United S t a t e s announced t h a t they had no claim on t h e i s l a n d and Mexico joined t h e excitement. The Dump Trouin was W d l y out of s i g h t when a Mexican gunboat, the

a r r i v e d (Dec.

13,

1897). Here s t a r t e d a diplomatic c o n f l i c t which was t o l a s t u n t i l 1931, when King Victor-Emmanuel I11 of I t a l y awarded the i s l a n d -to France, and which has become a text-book case f o r students of diplomacy and International Law. France and Mexico had agreed to submit the case to t h e monarch's a r b i t r a t i o n i n 1909, and both countries publish- ed h i s t o r i c a l r e p o r t s ( ~ e x i c o Llglll, France 1912) t o present t h e i r cases.

They a r e valuable documents, the French one especially, as it includes all t h e texts describing t h e i s l a n d to date, som of them unpublished u n t i l then.

During t h i s period, Mexico continued to l e a s e t h e phosphate deposits of the i s l a n d to various companies including the P a c i f i c Islands Company Ltd. of John Arundel. Also during that time, several n a t u r a l i s t s v i s i t e d t h e i s l a n d and made geological and zoological collections, among _them John Arundel in 1897 (t~harton 1898, Gamm 1899), Snodpass and Heller i n 1898, R. H. Beck in 1901 ( ~ e c k 1907), and the California Academy of

Sciences expedition i n 1905

levi in

1931). Casual v i s i t o r s added

specimens, e s p e c i a l l y s h e l l s , t o t h e collections of Clipperton a n i d b . For instance a group of s h e l l s i n the U. S. National Museum was received in 1897 from Mr. Arnheim, a ship chandler who had obtained them from s a i l o r s .

I n 1906 a l i g h t was b u i l t on t o p of the Rock, b u t during World War I, t h e i s l a n d wasabandoned i n a dramatic chapter of i t s history, and was forgotten. m e r e are q u i t e a few accounts of it f o r the period 1893-1.906, but hardly any information between 1917 and 1935. According t o a l e t t e r

i n the U. S. National Archives, several men from the Schooner Ethel M.

S t e r l i n ~ f r o m San Pedro landed on Clipperton on January 5, 1929, a f t e r sever& days of bad weather kept them on board ship o f f t h e island, and they collected samples of guano and lagoon water. The research vessel Velero I11 (Fraser 1943) stopped a t Clipperton on January 6, 1934, b u t landing was impossible, although some b i o l o g i c a l specimens were dredged a short distance off shore. I n January 1935, the F'rench t r a i n i n g ship Jeanne dlArc a f t e r several visits when-landing was impossible, c& ba.clr t o Clipperton, and a group of o f f i c e r s and midshipmen succeeded i n making a landing on January 26. They drew a map, wrote descriptions of the is- land, and collected some p l a n t and rock samples ( ~ a c r o i x 1939, Gauthier 1949). The s h i p ' s seaplane took some photopaphs. ^A bronze plaque sealed on the e a s t face of t h e Rock commemorated the v i s i t and established French ownership.

The next well-laown v i s i t was t h a t of President F. D. Roosevelt in J u l y 1938, during a cruise on the USS Houston. Dr. Waldo Schmitt of the U. S. National Museum, who had been i n v i t e d t o t r a v e l with t h e President as expedition naturalist,landed on Clipperton f o r a few hours and made

some very valuable c o l l e c t i o n s of p l a n t s and animaLs which were described i n a s e r i e s of papers ( W t h s o n i a n MW. Coll., 1939-1942).

During the second World War, Clipperton i s s a i d t o have been v i s i t e d by Japanese submarines; i n 1943 and 1944, the U. S. Navy made several reconnaissances of the i s l a n d and the famous Australian p i l o t Captain S i r P. G. Taylor landed h i s seaplane i n the lagoon. Such visits r e s u l t e d i n valuable descriptions (Byrd 1943, Taylor 1948) and photographs. In Dec.

1944, a small U. S. Weather Station was established. The ship (LST 563) bringing most of the material f o r i t s construction struck the reef, and

i t s great r u s t e d carcass, b a t t e r e d and much dismantled was s t i l l a con- spicuous landmark near the landing point on t h e northeast side i n August 1958, and served as a breakwater f o r small boats e f f e c t i n g a landing.

Rusting landing c r a f t , f u e l tanks and ammunition were s c a t t e r e d nearby across the land s t r i p . The weather s t a t i o n l a s t e d u n t i l October 1945, and i t s r u i n s a r e s t i l l recognizable as an abandoned quonset v i l l a g e i n the southwest coconut grove, the roads marked by tracked vehicles during t h a t period can s t i l l be followed most of the way around the island.

Since the end of World War 11, French Navy ships have been v i s i t i n g the i s l a n d regularly (Goua 1952, Bourgau 1954) and when landing turned out t o be possible, markers have been a.ttached t o the base of the Rock. I n 1958, t h e r e were 4 such comnemorative t a b l e t s . Curing t h e fiflzkes, scien- t i f i c groups from various institutSons stopped a t Clipperton and made

observations o r collections: t h e U. S . ITavy Electronics Laboratory i n May 1952 ( ~ e r t l e i n and W r s o n lg53), Scripps I n s t i t u t i o n of Oceanography

in Dec. 1954, and Oct. 1956 (Dawson 1957, Hertlein and W r s o n 19571, and U. S. Hydrographic Offlce, Nov. 1957. This l a s t group was maldng astron- omical and geophysical observations, and determining the exact position of t h e island. A French Navy o f f i c e r and M r . A. G. ObemdUer, chief geol- o g i s t of t h e France dtOutre-Mer accompanied t h e American geophysicists.

The geological c o l l e c t i o n s have been described i n an important r e p o r t (ObermUer 1959). Another valuable r e s u l t of t h i s expedition i s a c o l - l e c t i o n of photographs taken from a helicopter. In May 1958, Mr. W. L.

KLawe, of the Inter-American Tropical Tuna Conmission v i s i t e d Clipperton f o r a few hours and c o l l e c t e d some plants. F i n a l l y i n August and Septem- b e r 1958, the group of n a t u r a l i s t s from Scripps I n s t i t u t i o n of Oceanography

camped on the i s l a n d and made observations a s complete a s possible on the f l o r a , fauna, weather and other aspects. The group included four b i o l o g i s t s using skin-diving equipment t o study the m i n e fauna, three icthyologists, two entomologists, an ornithologist, two radio operators, and myself as botanist. The marine b i o l o g i s t s working on the r e e f and i n the surround-

ing ocean, collected marine animals and algae and made ecological obser- v a t i o n s and I concentrated my e f f o r t s on the land f l o r a and t e r r e s t r i a l and lagoon h a b i t a t s . Ho~rever, to give a complete view of the a t o l l , I s h a l l include b r i e f descriptions of c e r t a i n marine aspects from my l i m i t e d observations completed from information communicated t o me by my compan- ions and extracted from the l i t e r a t u r e . A l i s t of the recorded land f l o r a and fauna, t h e l a t t e r l a r g e l y compiled f r o m t h e l i t e r a t u r e , w i l l a l s o be included, in-so-far a s necessary t o give an account of the land ecology.

Extensive accounts of t h e zoology a r e being prepazed by the zoologists of t h e expedition, and other s p e c i a l i s t s .

WEATHER AND CL3MATE

The weather and climate of Clipperton Island a r e very poorly

known. The only weather records, outside of b r i e f mentions by v i s i t o r s , were collected from January t o October 1945 when a U. S. Navy s t a t i o n operated on t h e island, and during August and September 1958 when

Messrs. Limbaugh and Chess of t h e Scripps group made d a i l y observations.

The Navy records have never been used and are not available; the others w i l l . be u t i l i z e d be lo^^ (and see t a b l e 1).

The U. S. Hydrographic Office publishes climate and weather data f o r ocean areas from information transmitted by ships. However the ocean area where Clipperton Island l i e s i s not included: The Weather sunrmary f o r Central America ( L O . 531, U6 S. Hydrographic Office 1948) has no information f o r areas west of 1 C O W long. SO the 5-degree square f o r Clipperton is not discussed, Smmaries of P a c i f i c Ocean weather o f t e n do not extend f a r enough t o t h e e a s t to include the region of Clipperton. One reason f o r t h i s s t a t e of a f f a i r s is probably the small amount of information available i n an a r e a where there are no recording s t a t i o n s and few ships records. According to the World Meteorological Organization ( ~ n o n . 1957) t h i s i s one of t h e poorly known ocean areas of the world, from which more reports a r e much needed.

Information on Clipperton must be gained *om general sources such a s the Weather Bureau's Atlas of climatic c h a r t s of the ocean ( ~ c b n a l d 1938) and the U, S, Navy Atlas (1956).

The cl2mate of Clipperton Island i s an oceanic t r o p i c a l one, v i t h l i t t l e v a r i a t i o n i n temperature b u t w i t i z seasonal r a i n f a l l and storms.

The seasonal v a r i a t i o n i s correlated v i t h t r o p i c a l cyclone a c t i v i t y which reaches a maximum i n the eastern North P a c i f i c i n August, September and October. I n these months the i s l a n d m q u e n t l y experiences winds f r o m a southwest quarter, probably generated by t r o p i c a l cyclones to the north.

Temperature

According to t h e most recent compilation U. S. Navy 1956) t h e mean monthly air temperature i s never below 804 (26.7%) and only i n June i s it equal t o o r above 820F (27. ~ O C ) . From the same source, the mean a i r - s e a temperature difference f o r 3-month periods i s of the order of -l°F or a t most -lo to -3' ( a i r cooler than sea).

I n the period August

-

September 1958, the lowest recorded a i r

temperature was 750F (23.g0c) a t 1300 PDT ( p a c i f i c Daylight Tim, which _, i s t h e correct time f o r Clipperton island) taken during o r j u s t a f t e r a r a i n storm. The highest recorded temperature was 8 7 ' ~ ( 3 0 . 6 ~ ~ ) a l s o a t 1300. On sunny days it was q u i t e hot i n the sun, b u t never unbearably so. IVight temperatures were not recorded but seemed only s l i g h t w below day time temperatures.

Atmospheric pressure

Because Clipperton l i e s close t o the equator and i t s b e l t of

low pressures, t h e atmospheric pressure there is always low, with l i t t l e yearly v a r i a t i o n and v i t h probably regular and s l i g h t d a i l y v a r i a t i o n i n calm undisturbed weather. A t Colon, Panama

(u.

S. Hydrographic

Off i c e 1948) the yearly v m i a t i o n of mean monthly pressure i s only of 2 mb, t h e highest mean i n February (10U.18 rnb) and the lowest i n June (1009.14 mb). In the same a r e a of Panama, the total d a i l y range a t Cristobal averages 2.9 mb f o r t h e year, being about 3 mb f o r October t o March and 2 mb f o r June to August. The highest pressures there occur a t 1000 and 2200 local. time and the lowest a t about 0400 and 1600. From a large sampling of ships' reports, the maxima over the ocean a t

lo0

^lat.

occur a t t h e sane times, and the diurnal range i s 2.8 mb. From the s h o r t record available ( ~ l ~ g u s t

-

September 1958) the d a i l y v a r i a t i o n a t Clipperton seems t o f i t t h i s pattern, with a usual d a i l y range of the order of 2 mb. During the period of record, the total range of recorded pressures was 8 mb (1002 to 1010). The low values coincided with bad weather and probable cyclone a c t i v i t y i n the area. Since the records m e only f o r August and September nothing can be s a i d of any yearly p a t t e r n of atmospheric pressure variations.

Vinds

-

Surface winds a t Clipperton Island vary g r e a t l y during t h e year.

I n the winter the dominant winds a r e the northeast trades, although they a r e f a r from e r h i b i t i n g the type of constancy experienced on islands f a r t h e r west. I n the sunrmer the winds change considerably and f'rom

August to October they blow principally from the SW quarter. D n i n g t h a t

tinme, as t r o p i c a l cyclones dominate i n the area, winds a r e extremely var- i a b l e and t h e i r d i r e c t i o n can change rapidly during the day. Table 2 i s from &cDonaldfs atlas. Wind roses f o r the 5-degree squares are included i n the Hydrographic Office's P i l o t charts of t h e North Pacific Ocean and those f o r t h e square of Clipperton a r e reproduced from recent monthly charts i n t a b l e 4.

Nothing more i s known of the wind regime f o r the i s l a n d beyond t h i s generalized information except f o r the A u g u s t

-

September 1958 data and the observations of Taylor i n September

-

October 194.4 (P. G.

Taylor, 1948. I n 1958, t h e recorded observations of wind d i r e c t i o n

( s e e t a b l e 1 ) indicate a predominance of winds from the southwest quarter, especially SSW t o SW i n August and SW t o 31s i n September. These obser- vations f i t well with the generalized data of McDonald's a t l a s (see t a b l e 2). Recorded speeds were up t o 26 knots, but the majority of observations i n August indicated speeds of 10 knots o r l e s s and in September a n a j o r i t y of o b s e m t i o n s below 20 lmots. I n August, a t l e a s t , the strongest winds were not r x o r d e d . There i s only one record of calm and indeed t h e a l - most constant wind, whatever i t s direction, made l i v i n g on the island very comfortable.

Rains almost always came f'rom t h e southwest; from the northeast land s t r i p one could see the dark rain clouds engulf the coconut grove

on t h e opposite s i d e of the a t o l l , which promptly disappeared from view, cross t h e lagoon and eventually reach the northeast side, drenching it with a downpour of incredible suddenness and violence.

I n October 1956 (Linibaugh, personal communication) t h e winds were generally from the southwest, w i t h v e l o c i t i e s up t o 13 knots.

During h i s first s h o r t s t a y on Clipperton (from September gth, 1944) Taylor seems t o have encountered reasonably good weather, sunny and c l e a r much of t h e time, and he gives l i t t l e information on it in h i s book (1948).

M i n g t h e second v i s i t (September 21

-

October 14) t h e weather vas much worse, culminatbg in a hurricane (see p. 19 ). Strong winds from the

southwest were comrpon, with squaXLs up to 35 o r 45 knots (estimated) and frequent and r a p i d changes of surface wind d i r e c t i o n s were noted.

After spending some time on t h e island, Taylor summarized the gener- al p a t t e r n of winds and tleather as follows (p. 194):

"From observations from the tinae we had been a t t h e island, it seemed t h a t there was a f a i r l y regular weatlier cycle, with sometimes one period of the cycle m r e prominent.than others.

"Ve had a r r i v e d the second time i n the bad sector, when the wind

was i n the south-west and a t a time when t h i s phase was exaggerated, w i t h stormy conditions.

"As t h e wind swung i n t o north-west t h e weather had improved, and by t h e time it had come round t o north the sky was clean with s c a t t e r e d cumulus, and the surface wind was seldom more tha.n f i f t e e n knots. Fine weather with l i g h t winds and l i t t l e cloud then prevailed f o r several days as t h e breeze worked round e a s t t o south and back f o r south-west, when a high overcast would come over and t h e underlying c m u s would b u i l d up t o c m u l o nimbus with l i g h t n i n g and storms and the a i r w a s uneasy and wild till t h e wind s h i f t e d again toward north. The weather vent round t h i s cycle i n about a week, and always there was r a i n from t h e south-west o r west, and sometimes a shover from a l o c a l build-up of curnulus i n the f i n e periods. ^"

This sequence f i t s well t h e storm t r a c k s c o m n l y observed i n the Clipperton region, and has been represented i n a streamline/isotach reconstruction ( f i g . 2 ) prepared by Professor Pznage (personal comuni

-

c a t i o n 1960): "The cycle starts with a tropical. cyclone (c), moving NW o r WNW to the north of the s t a t i o n @lipperto$. ldinds veer t o W and NW and t h e weather inrproves as t h e e a s t e r n portion of a s m a l l high pressure c e l l ( A ) follows the storm c i r c u l a t i o n across the s t a t i o n . Winds de- crease f u r t h e r but m a t h e r s t a y s f a i r a s the divergent portion of a c o l preceding t h e next cyclone moves over. The cycle i s complete when strongly convergent Sf4 winds associated with the next cyclone s e t in." %is recon- s t r u c t i o n a l s o compaxes well with the sequences recognized f r o m the 1958 data (P* 16 ) *

Tropical storms and hurricanes

While not a s numerous and destructive as they are i n the Caribbean area o r the Chiaa Sea, t r o p i c a l s t o m and hurricanes are common i n t h e southeast North Pacific, with an average of a t l e a s t 6 storms every year, two of which reach llwricane strength. Hwd (1929 p. 45, 1948) assembles t h e cyclonic storms of t h i s region i n t o 4 classes: 1. The coastwise storm, t h a t r u n p a r a l l e l t o the Central American and Mexican coast, 2.

those t h a t s t r i k e perpendicularly upon the Mexican coast, 3. cyclones of the Eevillagigedo Islands and 4. cyclones v e s t of the 125th meridian, The l a s t need not concern us here. The storms of the f i r s t c l a s s o r i g i n - a t e somewhere along the Amrican coast, often i n the Gulf of Tehua.ntepec o r south of it, o r sometimes perhaps as far south as the Gulf of Darien (1ves 1952). They t r a v e l usually northwestmxd i n a course p a r a l l e l t o t h e coast; some swing inland over the Mexican west coast, some t r a v e l f a r i n t o the G u l f of California; a few cross over to the Caribbean area, and conversely, some storms originating i n the Caribbean t r a v e l t o the Pacific side. The s t o m of t h i s c l a s s a r e far to the e a s t of Clipperton and probably never a f f e c t it.

The storms of the 2nd c l a s s occur f a r t h e r west and t r a v e l i n a north- ward direction. Those of c l a s s 3 t r a v e l i n a west-north-west d i r e c t i o n and a r e mostly observed north of Some of the storms of these 2 classes may f o m near Clipperton, or pass by it. There a r e a l s o s t o m i n t h i s a r e a which do not r e a d i l y f i t i n the 4 classes, such as some vhich t r a v e l i n a westerly course o r sometimes even somewhat south of we st.

The occurrence of t r o p i c a l storms i n the southeast North P a c i f i c i s seasonal, and t h e monthly d i s t r i b u t i o n i s given by Visher (1925) as follows:

Dec. to Feb. 1% each MarchtoMay 0

June

J u l y 5%

11%

Aug 15%

Sept

.

³⁴⁷⁷

Oct. 24%

Nov

.

^5%

Because Clipperton i s removed from shipping l a n e s and has only been inhabitea occasionally and f o r s h o r t periods of time, h i s t o r i c a l records of s-Lorn an8 hurricanes a r e poor. Hotrever, some of the storms which a r e reported west of l l o O W and t r a v e l l i n g i n a northwest d i r e c t i o n may have originated near the i s l a n d o r passea it, e i t h e r a s storms or, rarely, a s f u l l - s i z e hurricanes. A t r o p i c a l storm, it must be remembered, need not score a d5rect h i t , o r even have reached i t s f ' u l l development, to a f f e c t an a t o l l lyirtg only a few meters above sea level. Even storms t r a v e l l i n g several hund~ed kilometers away m y generate storm waves high enough to b a t t e r the i s l a n d and even to flood the lower areas of the land s t r i p .

The older records of storms i n the southeastern North Pacific a r e l i s t e d by Redfield (1856), t h e ikutsche Seemrte (1895), Visher (1922, 1925) and Hurd (1929, 1948). In recent years, t r a c k s of storms have been p l o t t e d by the >Jea.ther Bureau i n the National Summary of Climato-

l o g i c a l Data and t h e Mariners Weather Log, and by the Hydrographic Office on t h e P i l o t Charts.

From these records the l i s t on t h e following pages has been

extracted. Some of t h e storms may have passed Clipperton Island close enough t o a f f e c t it, o r may have formed near it. Those marked with a -:- were reported very near the island, o r experienced a t it.

Date

-

*1915, June?

1915, Sept. 4-5 1922, July 31 1922, Sept. 9-10 1922, Oct. 13-16 1928, Oct, 15-16 1936, Oct. 27-29 1940, Sept. 22-24 1940, Oct. 6-11

*19f&, Octa 12 1955, June 5-8 1955, June 7-10 i95, May 17-19

*1957, J u l y U-26

Place r e ~ o r t e d

-

Source

Clipperton Morris 1934

1 0 9 ~ 4 0 ' K h b a l l 1915 118

W

Visher 1925 113°f&t Visher 1925 and

Hurd 1948

lloO

Hurd 1948 113O29 1 11

106' n

11o0 II

lloO

^I1

Clipperton Taylor 1948

l.4.

5O 111. lo Nt a 1 Surmar y 1 1 . 4 O 107.4~ ¹¹

10.3~ 109.5' II

and Mar, i;.ec..ther Log, March 1958

Skip report in^, and notes Storn destroyed Mexican canp C a l l i o ~

Besse r ~ e r

A very intense and very large hurricane

See be

Havaiian Citizen; noving N

Hanaiian Fishermn; center charted a t 11.5', 109.7O, noving NV3

Arapahoe; center e s t i r ~ t e d a t 13.7', 111,6O, aoving 1

Gravel Park; rloving lil then WNI"J

--

Pate

_* Place r e p o r t e d Source s Ship r e p o r t i n g , and n o t e s

( c ) Aug. 17-25

(d) Aug, 27

-

^{Sept. 3}

1961, J u l y 10

J u l y

.U

C l i p p e r t o n

Clipperton

"A s m l l depression o r t r o p i c a l s t o r n moved on a westerly course j u s t n o r t h of t h e s t a t i o n .

"The c e n t e r of a s m l l t r o p i c a l s t o r n passed a c r o s s t h e s t a t i o n f r o u SE t o EJBJ t h e n p o s s i b l y

i n t e n s i f i e d n o t f a r t o t h e NW.

"A depression appeared t o develop and slowly i n t e n s i f y in t h e Clipperton a r e a f i n a l l y noving t o t h e N of t h e s t a t i o n on t h e 3rd.

It continued t o uove N and t h e n NFJ being f i r s t l o c a t e d nhen rrinds on t h e i s l a n d of Roca

P m t i d a (1911, 1 1 2 ~ ~ ) increased t o SE 40 knots a t 1200 GhiT on t h e 6th. By t h i s t i n e , o r s h o r t l y t h e r e a f t e r n i n d s of over 100 h o t s

had developed near t h e s t o r u center.f1 b h e ^I s t o r m rientlioned a r e recorded in _{P -3} l e a t h e r Log f o r March 1959J _I None of t h e s t o r n s r e p o r t e d f o r 1959 in Mariners Weather Log, ,March 1960, s e e m l i k e l y t o have a f f e c t e d Clipperton Island.

None of t h e s t o r u s r e p o r t e d f o r 1960 i n Mariners Weather h g , Mmch 1961, seerm l i k e l y t o have a f f e c - t e d Clipperton Island.

1 6 ' ~ 1uq,ir Mar. Wecther Tropical s t o r n Joanne ~ o v i n g n e s t m r d ; on t h e Log, Sept. 1961 l l t h , yfinds near c e n t e r 60 knots.

Hurricane Kathleen noving northnestvard;

caxirnr:. ninds 70 knots.

Date

-

Place reported

1961, J u l y 1 5 1 9 O 13g0 J u l y 16 16'

July

l-4 u0

t o J u l y 15-18 200 J u l y 20 15O

1961, Sept. 6-8 ^{1 7 O}

Source s

---

M;LT. Weather Log

Ship r e p o r t i w , m d notes Kathleen

Kathleen cioving west, 60 knot ninds near t h e center.

Hurricane Liza, ;!inds near t h e c e n t e r 70 knots.

Liza coving nest-northnestnard, r a x i ~ u n ninds near 50-60 knots.

T r o p i c a l s t o r n Madeline (see p. 231, noving nestnard, ninds near c e n t e r 55 knots.

Tropical s t o r n Naoni, ninds 30-50 knots. I

Tropical s t o r n O r l a noving northnestnard, ^I ninds 60 knots.

The following i s condensed from Taylor

'

s book (1948, pp. 224- 254), the only eye-witness account of a Clipperton Island hurricane.

October 12, 1944. Soon a f t e r dam, f r e s h breeze from t h e north, sky dark, heavily overcast, nimbus hiding the tops of cumulus, and f a s t moving clouds below. Altimeter of a i r c r a f t s e t at zero read 29.95 (1010.8 mb), low on the scale of e a r l i e r d a i l y readings, but no lower than had already been recorded. A t breakfast t h e , the fresh puffs on the lagoon had changed t o squalls, the wind swinging around as i t s force increased soon reaching 50 lmots. Rain came i n blinding sheets, drenching the camp.

The s q u a l l passed, but the wind hardened i n t o a steady blow, and within an hour of coming ashore f o r breaMast, l i t t l e remained of the c a p . (This camp was on the west lagoon shore, j u s t north of North pincer).

Suddenly t h e wind eased to 30 knots, but soon a f t e r swung i n t o e a s t and became worse. Half an hour l a t e r there was another sli&\t easing of the wind, but soon it swung more towards south and became more violent.

"About two hours a f t e r the f i r s t s q u a l l s the wind swung nearer t o south...

Toe Rock was b l o t t e d out and the lagoon was sweeping towards us i n a trail of water l i k e spray from many hoses, reaching from shore t o shore and

leaving no d e f i n i t i o n between sky and lagoon. It was a f a n t a s t i c sight.

. .

^"

The wind w a s s t i l l blowing with hurricane force, estimated as between 80 and 100 knots. A l i t t l e before noon it svung t o south and the lagoon, waves abated somewhat, b u t danger from the ocean became greater. In t h e

coconut grove: "the heads of the p h s were s t w g back i n windblown fronds l i k e the h a i r of a g i r l i n t h e wind. The t a l l e r palms were bent l i k e tight-strung born, and held till it seemed t h a t t h e i r spines must break. Their fronds were awash i n t h e b l a s t of a i r . .

.

And now, instead of t h e horizon dark w i t h cloud against the f l a t r i m of t h e land, there was a cold white stream of breaking surf, v i s i b l e above t h e land, and roaring madly at the island... Already only the reef was stopping the r o l l e r s , which

...

were higher than the land." If the hurricane were t o s w i n g i n t o southwest the ocean would flood the s t r i p of land where the camp was. %ying t o reach the coconut grove only 200 yards away, two men went f i r s t oceanward t o seek some s h e l t e r on t h e ocean side of t h e beach ridge, but the sea was a b e a d y f a r up the beach, and kept r i s i n g . "It ms roaring by now not two f e e t below the"sp of t h e bank. The surge was

sending l i t t l e r i v e r s t r i c k l i n g through the stones over the top... Now t h e r e were no r o l l e r s breaking on the reef. The whole ocean was t e a r i n g by i n a roaring flood of vater, clawing a t the island." The pigs and some b i r d s had t a k e n s h e l t e r i n the coconut grove. ^{. .}

About 3 p.m., t h e r e was a d e f i n i t e lightening i n t h e sky and a s l i g h t easing of the wind, which d e f i n i t e l y slacked up a few minutes l a t e r . BEtck i n the a i r c r a f t , t h e altinoeter showed s t e a d i l y r i s i n g pres- sure. By 5 p.m., the wind had dropped to a hard blow of about 4.0 knots, and by night, eased to about 30 knots. The next day was sunny, with some showers and a l i g h t breeze from t h e south.

Two Catalina flying-boats were mchored in t h e lagoon during the storm and barely survived it. On the 14th, with f i n e weather and a l i g h t southerly wind,,Captain Taylor took off i n h i s flying-boat t h e F r i g a t e Bird f o r the Marquesas and Bora Bora.

Rainfall

The Pacific coast of Central America and the ocean area between it and Clipperton Island have a &ci&dly seasonal p a t t e r n of r a i n f a l l ,

with the months f r o m December o r January to April o r May d r i e r than the sunnner and f a l l . This p a t t e r n apparently i s s t i l l v a l i d westward as far a s Clipperton Island. The SaUing Directions

(u.

S. Hydrographic Office, 1951) indicate that there i s a "dry" season i n December to May, but j u s t how dry i s not known. This information i s probably based,

i n part a t l e a s t , on observations furnished by the guano workers who l i v e d on the i s l a n d during the last years of the 19th and the first yeaxe of the 20th centuries, as it was abeady included in the 1902 edition of the Sailing Directions. For instance, P. J. Hennig kept notes on t h e weather during h i s s t a y a s "keeper" of Clipperton and i s s a i d t o have forwarbd them to t h e Hydrographic Office w i t h hia map (cf. p. 6 ) - I could not f i n d a record of h i s data, but a newspaper account (&on. 1897) quotes excerpts from them:

"Mr. Hennig, who i s a man of a b i l i t y as well a s patriotism, kept an accurate l o g of the i s l a n d from October 1, 1896 to A u g u s t 5, 1897.

He has presented the l o g to the hydrographic office, and it is the first valuable record of the Clipperton conditions.

"October had -st d a i l y rains, w i t h southerly and southwesterly

winds. There was about a s much r a i n i n November, several heavy thunder storms and a few h83"d sqUaUs. December was s u l t r y , w i t h many rainy days. L i t t l e r a i n f e l l i n January, and the weather was hot. The word

'pleasantt occurs frequently in the February records. Severe thun&r storms were again noted i n March, April and May. The record of t h e Kin- kora d i s a s t e r is a s follows:

"Friday, April 30th--Wind N. N, S. Moderate breeze with s q u a l l s i n f i r s t part; then gentle breeze with squalls and l i g h t rain, b u t m s t l y f a i r , hot, s u l t r y weather. Heavy surf. A t 8 a.m., stranger tn W. S. W.

i n sight.

"Saturday, May 1st--Vind N. E. by E. Mo&rate weather; heavy aurf.

Stranger coming around e a s t side of i s l m d , f l y i n g B r i t i s h colors.

Proved t o be ship Kinkora, Belfast, water-logged, and bad steering.

Beached a t 5 o 'clock. All hands saved.

"Easterly and northerly win& prevailed From the beginning of Novem- ber u n t i l June; then the south and southwest winds returned.

. .

"June and J u l y were hot months, with occasional r a i n s and squalls."

In addition, the manuscript diary of John Arundel f o r J u l y and August 1897 (which I have seen by courtesy of Mr. H. E. Maude, and which i s quoted here with the permission of Mrs, Sydney Aris) includes t h i s o b s e m t i o n of one of the workmen, who "says it r a i n s nearly every day

-

^showers

-

though you may have 2 o r 3 days without

-

but the winter months a r e a s a r u l e the d r i e s t

-

though he has never known a month w i t h - out r a i n

. . .

I n the winter dry season

-

^{3 o r 4 ms.} you have North E a s t trades. ^"