Pacific Hurricanes

Warning Systems For South

A Review By J. P. S.

11HTH another destructive hurri ?▼ cane season behind us ip wards of 500 lives were lost and j-eat damage was done in Fiji, the view Hebrides, Solomons and xouisiades this year—there naturally i speculation as to whether all •ossible measures are being taken o evade these almost annual visita ions.

Islands residents are asking whether he present hurricane-tracking and yarning organisation can be im proved, and just what is being done n other hurricane areas of the vorld to avoid damage and, above ill, loss of life. Is the weakness— f any—in the meteorological or the Administrative sphere?

Much, though by no means all, >f the damage done in the South ’acific occurs within New Zealand’s irea of responsibility—one of the world’s largest meteorological zones, ;xtending from the equator to the s ole, and from 160 degrees East .ongitude eastward across ihe South ’acific Islands area to beyond French Oceania. The tropical portion of his zone is under direct supervision rom Nadi Airport, Fiji, which is he New Zealand Meteorological Service's Islands headquarters.

Therefore, for a reply to some of hese questions, we approached Dr. . F. Gabites, who, as head of the Research Section of New Zealand’s ‘Met”, has responsibility for keeping he Service abreast of the latest de velopments, examining the virtues of he latest methods by on-the-spot nvestigations overseas where neces lary, and making recommendations.

Dr. Gabites’ findings disagree con siderably in some respects with articles that have appeared in the oopular press in recent years.

AT regular, internationally-agreed intervals, day and night, through out the year, over 50 observing stations in the South Pacific tropical irea report their instrument readings :o Nadi. A few take observations of winds high above the earth. All send in pressure, temperature, cloud, surface wind, rainfall, state of sea, 2tc. These are simply observation stations, with no responsibility other than to accurately report their instrument-readings regularly. These are not forecast or warning stations.

The entire responsibility for tracking

and warning rests with the forecast ing staff at Nadi where, with all observations entered and the pressure and wind systems drawn in on the current weather-map of the area, only they are in the immediate position to assess the situation within an hour of the reports arriving by radio.

Later, this mass of information, first in original form as re ceived from the individual Islands observers, and later in digested form a coded picture of the map as drawn at Nadi—is broad cast by high-powered transmitters to the world at large from Nadi.

There are no secrets in Met to day. Nothing is done behind closed doors. Anyone with a pencil, a knowledge of morse, and a copy of the International meteorological codes, may have at his disposal, every three hours, all the informa tion required for drawing his own

tnap if he so wishes—and also a :opy of just how Nadi has drawn the nap and assessed the situation.

But only experience can provide he knowledge required to make a '©recast —and there is nothing more ricky to forecast than the precise lirection of movement of a hurri cane.

Dr. Gabites points out that, where is in the past the curving paths of he hurricanes could be plotted only n a very general way from the sparse information available, it has ately been possible by the use of lircraft and radar to follow in detail he tortuous paths of West Indian md North Pacific hurricanes. The racks show changes in speed and lirection and even complete circles hat could never have been deduced vith certainty from the normal jbservation networks. The precise novements from hour to hour are n fact, according to present know edge, about as predictable as the novements of one of those little swirling eddies in the Rewa River, is it wanders seaward from Nausori Bridge. f\NE system of hurricane tracking which has received publicity at ntervals since World War II is the seismic method. This is based on

the fact that the violent agitation of the sea sets up minute earth tremors or “microseisms” which may be detected and their distance approxi mately determined from the record ings at three inter-connected seismic stations a few miles apart.

Science has long been aware of these characteristic storm vibrations, but probably the first practical use was made of the method in the Caribbean area during the last war.

Radio silence precluding the trans misssion of observations from ships in the area, the US Navy, seeking a way out, became interested in the ex perimental work of the Rev. Fr. J. E.

Ramirez, S.J., of St. Louis University.

Results seeming hopeful, the Joint Chiefs of Staff set up a group of seismic recorders at tthe US Navy base at Guantanamo Bay, Cuba, and one at Richmond, Florida, in 1944; then, a year later, a station at San Juan, Puerto Rico, and another at Richmond.

According to Rev. Fr. James B.

Macelwane, S.J., Dean of St. Louis University, in his book When the Earth Quakes, published 1947, the re sults achieved from this group of re cording stations were regarded as most encouraging. Storms and hurricanes were said to have been accurately spotted at distances of up to 2,000

miles for severe storms and pro gressively less for smaller dis turbances.

On the strength of these results the US Navy later established similar stations in the Northwest Pacific, at Guam, Manila and Japan—and the Australian Met Service, late last year had the aid of a similar station, set

up in Brisbane, at the University.

This apparently, was the first micro seismic recorder station of improved design to be operated under control anywhere in the world, and cost £lO,OOO to establish.

These developments indicate that the seismic method can become a valuable one. It has been repeatedly

reported that as a hurricane-tracker over the ocean, the method has no equal—excepting only visual tracking by aircraft.

DR. GABITES, however, is far less enthusiastic. He emphasises that only under certain circumstances, and with certain types of hurricane dis

turbances, is the method iii any wa;j accurate; that considerable error have been observed; and that onl where all normal reporting method are absent—such as over an ope ocean area, devoid of island or shi reporting stations —is the method jus tilled at all.

New Zealand has carried out e? perimental work, and Dr. Gabih himself has inspected some ot tr overseas seismic stations to satis, himself of results at first-hand, r considers that insofar as the Sou Pacific Islands area is concerned the area where damage is done seismic net comprising two or thr interconnected stations would pro ably be a useful supplement to exi< ing observing networks, but wou be disproportionately expensive equipment, manpower and mamte ance. The same expenditure devot to improving the weather reporti networks would be of greater a more direct advantage.

Dr. Gabites considers that the or very accurate hurricane-tracki method far from land is the use relays of aircraft. The Americans using this method in the North Pa fic and elsewhere —but no suita heavy-bomber type of aircraft is present available for such work the South Pacific. For short rai

r ork—say within 100 miles—radar lethods are accurate; but the equip lent and operational costs of radar r ould be high. A single station may ast well over £lO,OOO to establish— nd a hurricane may not pass within s range in years.

No doubt a radar station would ffectively guard Suva, say, and pro ide reliable warning an hour or two sfore the hurricane hit—but it would at prevent the hurricane from doing ic usual damage.

N Suva, in the past, there has been ■ criticism of Met in regard to arnings. When there has seemed a al possibility of the hurricane hitting le capital, Met has issued a final arning. If the hurricane has then at arrived in Suva, business houses ive complained of the expense and aste of time involved in battening awn and unbattening again.

On the other hand, when a hurri me has seemed unlikely to strike Liva and no final warning has been sued. Met has of course again been lamed for falling down on the job hen the hurricane has struck.

Would the very high cost of a idar station to avoid this situation ; warranted —or would it be better >r Met to invariably issue a full arning and for business houses to ose down so long as the period of icertainty lasts?

Dr. Gabites considers that it is up » the community—not Met to decide hat should be done in regard to nal warnings. The problem is a rea-1 tie in heavily populated places like ig South-east coast of the U.S., here the cost of closing down in jadiness for a hurricane is very igh indeed.

The question to be decided is hether, in a moderate-sized town ke Suva—or in Vila, Apia, or oumea—it would always be advis ee to make full preparation as soon > the slightest doubt develops. Or ould the cost of doing so be greater lan the cost and maintenance of litable radar stations at the Capitals -or of groups of stations scattered trough the more populous South acific areas? Or is it better to take te risk, as at present?

Ji EANWHILE, people in the South Pacific should realise that no here does there exist today the leans of accurately reporting or pre cting the movements of a hurricane; lat the means are available—at very gh cost—for localised areas only; id that once a warning has been sued for their general area (say, ithin several hundred miles), it is ise for them to assume that they e going to be hit and to take full

measures to prepare their buildings for the blow.

People living in the hurricane area should accept the fact that, sooner or later, they are going to be hit, and they should have some safe refuge, well above sea level, planned in ad vance.

There would seem no sound reason why native villages should not es tablish well-built shelters, of solid yet simple type, at little expense.

Native houses rarely withstand a hurricane, and they frequently prove to be death-traps, killing the inmates as they collapse. School children should be taught that the greatest danger, once the blow commences, is

in being out where there is enormous risk from flying debris. People should also realise that wh en a hurricane P asses directly across their area there w *d be a temporary complete calm ~-which will very soon be followed by an equally violent blow from the opposite direction. Lives are fre- T uent ly lost through people coming

ito the open when this calm arrives, elieving that the blow is over.

Material damage, especially to plan itions, can never be overcome, but mch could be done towards saving ves and buildings if prompt action i taken.

Certainly there has been no hum ane in the South Pacific area that as not been adequately reported by le existing Met Organisation in the ast 10 years. If Met has fallen down t all it may have been in its reluc ince or failure to advise the public f its limitations in ability to pre ict the exact movement of hurri anes, thus encouraging over-con dence.